Added docs for the @unit tag

docs/mission-modeling/activity-types/activity-type-metadata.md

@@ -0,0 +1,102 @@
+# Activity Type Metadata
+
+Metadata of activities are structured such that the Aerie annotation processor can extract this metadata given particular keywords. Currently, the annotation processor recognizes the following tags:
+
+- `brief_description`
+- `computedAttribute`
+- `contact`
+- `resourceName`
+- `subsystem`
+- `units`
+- `verbose_description`
+
+These metadata tags are placed in a [Javadoc](https://en.wikipedia.org/wiki/Javadoc) style comment block above the activity type to which they refer. For example:
+
+```java
+/**
+ * @subsystem Data
+ * @contact camargo
+ * @brief_description A data management activity that deletes old files
+ */
+ @ActivityType("DeleteOldFiles")
+```
+
+## Units
+
+The Aerie annotation processer can leverage the `@unit` tag to parse and display units for Parameters, Computed Attributes, and Resource Types.
+
+### Parameters
+
+There are 2 valid locations to parse a parameters units, on the parameter itself if it is a proptery of a class, or on the record defining an activity type. When you define the units as part of a record type you need to include the `@param` you're defining the units for on the previous line.
+
+```java
+/**
+ * @param duration
+ * @unit seconds
+ * @param energyConsumptionRate
+ * @unit kWh
+ */
+@ActivityType("RunHeater")
+public record RunHeater(long duration, int energyConsumptionRate)
+```
+
+```java
+@ActivityType("RunHeater")
+public class RunHeater {
+  /**
+   * @unit seconds
+   */
+  @Paramter
+  public long duration;
+
+  /**
+   * @unit kWh
+   */
+  @Parameter
+  public int energyConsumptionRate;
+}
+```
+
+### Computed Attributes
+
+Units can be specified for computed attributes as well, this happens on the record that defines the `ComputedAttributes`. The `@unit` tag here needs a `@computedAttribute` tag on the previous line the annotation processor knows which property to assign the units to.
+
+```java
+  /**
+   *
+   * @computedAttribute durationInSeconds
+   * @unit seconds
+   * @computedAttribute energyConsumptionRate
+   * @unit kWh
+   */
+  @AutoValueMapper.Record
+  record ComputedAttributes(
+    long durationInSeconds,
+    int energyConsumptionRate
+  ) {}
+```
+
+### Resource Types
+
+Units for resource types can be defined in two places similar to parameters. The first is on the `Mission` class where resources are registered, alternatively it can be defined on the resource itself. The units defined here need to have a `@resourceName` tag with the name of the resource on a previous line.
+
+```java
+/**
+ * @resourceName /flag
+ * @unit A, B
+ */
+public final class Mission {
+  /**
+   * @resourceName /fruit
+   * @unit number of fruit
+   */
+  public final Register<Accumulator> fruit;
+
+  public final Register<Flag> flag;
+
+  public Mission(final Registrar registrar, final Configuration config) {
+    registrar.discrete("/flag", this.flag, new EnumValueMapper<>(Flag.class));
+    registrar.real("/fruit", this.fruit);
+  }
+}
+```

docs/mission-modeling/activity-types/introduction.mdx

@@ -27,17 +27,3 @@ In order for Aerie to detect an activity type, its class must be annotated with
 ```
 
 By doing so, the Aerie annotation processor can discover all activity types declared in the mission model, and validate that activity type names are unique.
-
-## Activity Type Metadata
-
-Metadata of activities are structured such that the Aerie annotation processor can extract this metadata given particular keywords. Currently, the annotation processor recognizes the following tags: `contact`, `subsystem`, `brief_description`, and `verbose_description`.
-These metadata tags are placed in a [Javadoc](https://en.wikipedia.org/wiki/Javadoc) style comment block above the activity type to which they refer. For example:
-
-```java
-/**
- * @subsystem Data
- * @contact camargo
- * @brief_description A data management activity that deletes old files
- */
- @ActivityType("DeleteOldFiles")
-```