[embedded-elt] Add additional docs to resources (#20384)

## Summary & Motivation

Adds missing docs for Sling's replication

## How I Tested These Changes

python_modules/libraries/dagster-embedded-elt/dagster_embedded_elt/sling/resources.py

@@ -126,63 +126,94 @@ class SlingTargetConnection(PermissiveConfig):
 
 @public
 class SlingConnectionResource(PermissiveConfig):
-    """A representation a connection to a database or file to be used by Sling. This resource can be used as a source or a target for a Sling sync.
+    """A representation of a connection to a database or file to be used by Sling. This resource can be used as a source or a target for a Sling syncs.
 
-    This resource is responsible for the managing how Sling connects to a resource. To manage how Sling uses this connection (as a source or target), see the specific source_options or target_options in the `build_assets_from_sling_stream` function.
+    Reference the Sling docs for more information on possible connection types and parameters: https://docs.slingdata.io/connections
+
+    The name of the connection is passed to Sling and must match the name of the connection provided in the replication configuration: https://docs.slingdata.io/sling-cli/run/configuration/replication
+    You may provide either a connection string or keyword arguments for the connection.
 
     Examples:
         Creating a Sling Connection for a file, such as CSV or JSON:
 
         .. code-block:: python
 
-             source = SlingConnectionResource(type="file")
+             source = SlingConnectionResource(name="MY_FILE", type="file")
 
         Create a Sling Connection for a Postgres database, using a connection string:
 
         .. code-block:: python
 
-            source = SlingConnectionResource(type="postgres", connection_string=EnvVar("POSTGRES_CONNECTION_STRING"))
-            source = SlingConnectionResource(type="mysql", connection_string="mysql://user:password@host:port/schema")
+            postgres_conn = SlingConnectionResource(name="MY_POSTGRES", type="postgres", connection_string=EnvVar("POSTGRES_CONNECTION_STRING"))
+            mysql_conn = SlingConnectionResource(name="MY_MYSQL", type="mysql", connection_string="mysql://user:password@host:port/schema")
 
-        Create a Sling Connection for a Postgres or Snowflake database, using keyword arguments, as described here:
-        https://docs.slingdata.io/connections/database-connections/postgres
+        Create a Sling Connection for a Postgres or Snowflake database, using keyword arguments:
 
         .. code-block::python
 
-            source = SlingConnectionResource(type="postgres", host="host", user="hunter42", password=EnvVar("POSTGRES_PASSWORD"))
-            source = SlingConnectionResource(type="snowflake", host=EnvVar("SNOWFLAKE_HOST"), user=EnvVar("SNOWFLAKE_USER"), database=EnvVar("SNOWFLAKE_DATABASE"), password=EnvVar("SNOWFLAKE_PASSWORD"), role=EnvVar("SNOWFLAKE_ROLE"))
+            postgres_conn = SlingConnectionResource(
+                name="MY_OTHER_POSRGRES",
+                type="postgres",
+                host="host",
+                user="hunter42",
+                password=EnvVar("POSTGRES_PASSWORD")
+            )
+
+            snowflake_conn = SlingConnectionResource(
+                name="MY_SNOWFLAKE",
+                type="snowflake",
+                host=EnvVar("SNOWFLAKE_HOST"),
+                user=EnvVar("SNOWFLAKE_USER"),
+                database=EnvVar("SNOWFLAKE_DATABASE"),
+                password=EnvVar("SNOWFLAKE_PASSWORD"),
+                role=EnvVar("SNOWFLAKE_ROLE")
+            )
     """
 
-    name: str = Field(description="The name of the connection.")
-    type: str = Field(description="Type of the source connection. Use 'file' for local storage.")
+    name: str = Field(
+        description="The name of the connection, must match the name in your Sling replication configuration."
+    )
+    type: str = Field(
+        description="Type of the source connection, must match the Sling connection types. Use 'file' for local storage."
+    )
     connection_string: Optional[str] = Field(
-        description="The connection string for the source database.",
+        description="The optional connection string for the source database, if not using keyword arguments.",
         default=None,
     )
 
 
 @experimental
 class SlingResource(ConfigurableResource):
-    """Resource for interacting with the Sling package.
+    """Resource for interacting with the Sling package. This resource can be used to run Sling replications.
+
+    Args:
+        connections (List[SlingConnectionResource]): A list of connections to use for the replication.
+        source_connection (Optional[SlingSourceConnection]): Deprecated, use `connections` instead.
+        target_connection (Optional[SlingTargetConnection]): Deprecated, use `connections` instead.
 
     Examples:
         .. code-block:: python
 
-            from dagster_etl.sling import SlingResource
+            from dagster_etl.sling import SlingResource, SlingConnectionResource
+
             sling_resource = SlingResource(
-                source_connection=SlingSourceConnection(
-                    type="postgres", connection_string=EnvVar("POSTGRES_CONNECTION_STRING")
-                ),
-                target_connection=SlingTargetConnection(
-                    type="snowflake",
-                    host="host",
-                    user="user",
-                    database="database",
-                    password="password",
-                    role="role",
-                ),
+                connections=[
+                    SlingConnectionResource(
+                        name="MY_POSTGRES",
+                        type="postgres",
+                        connection_string=EnvVar("POSTGRES_CONNECTION_STRING"),
+                    ),
+                    SlingConnectionResource(
+                        name="MY_SNOWFLAKE",
+                        type="snowflake",
+                        host=EnvVar("SNOWFLAKE_HOST"),
+                        user=EnvVar("SNOWFLAKE_USER"),
+                        database=EnvVar("SNOWFLAKE_DATABASE"),
+                        password=EnvVar("SNOWFLAKE_PASSWORD"),
+                        role=EnvVar("SNOWFLAKE_ROLE"),
+                    ),
+                ]
             )
-
     """
 
     source_connection: Optional[SlingSourceConnection] = None
@@ -283,7 +314,7 @@ def sync(
         encoding: str = "utf8",
     ) -> Generator[str, None, None]:
         """Runs a Sling sync from the given source table to the given destination table. Generates
-        output lines from the Sling CLI.
+        output lines from the Sling CLI. Deprecated, use `replicate` instead.
         """
         if (
             self.source_connection
@@ -331,8 +362,17 @@ def replicate(
         replication_config: SlingReplicationParam,
         dagster_sling_translator: DagsterSlingTranslator,
         debug: bool = False,
-    ):
-        """Docs go here."""
+    ) -> Generator[MaterializeResult, None, None]:
+        """Runs a Sling replication from the given replication config.
+
+        Args:
+            replication_config: The Sling replication config to use for the replication.
+            dagster_sling_translator: The translator to use for the replication.
+            debug: Whether to run the replication in debug mode.
+
+        Returns:
+            Optional[Generator[MaterializeResult, None, None]]: A generator of MaterializeResult
+        """
         replication_config = validate_replication(replication_config)
         stream_definition = get_streams_from_replication(replication_config)
 
@@ -375,7 +415,7 @@ def replicate(
             )
 
     def stream_raw_logs(self) -> Generator[str, None, None]:
-        """Returns the logs from the Sling CLI."""
+        """Returns a generator of raw logs from the Sling CLI."""
         yield from self._stdout