Merge pull request #67 from Nezteb/master

Update docs and error message

README.md

@@ -83,7 +83,7 @@ defmodule MySystem.MixProject do
 
   def project do
     [
-      compilers: [:boundary, :phoenix, :gettext] ++ Mix.compilers(),
+      compilers: [:boundary] ++ Mix.compilers(),
       # ...
     ]
   end

demos/my_system/mix.exs

@@ -7,7 +7,7 @@ defmodule MySystem.MixProject do
       version: "0.1.0",
       elixir: "~> 1.10",
       elixirc_paths: elixirc_paths(Mix.env()),
-      compilers: [:boundary, :phoenix, :gettext] ++ Mix.compilers(),
+      compilers: [:boundary, :phoenix] ++ Mix.compilers(),
       start_permanent: Mix.env() == :prod,
       deps: deps()
     ]

lib/boundary/mix/tasks/compile/boundary.ex

@@ -72,6 +72,7 @@ defmodule Mix.Tasks.Compile.Boundary do
   warning: forbidden reference to MySystemWeb
     (references from MySystem to MySystemWeb are not allowed)
     lib/my_system/user.ex:3
+    See https://hexdocs.pm/boundary/Mix.Tasks.Compile.Boundary.html for details.
   ```
 
   Since the compiler emits warnings, `mix compile` will still succeed, and you can normally start
@@ -314,7 +315,8 @@ defmodule Mix.Tasks.Compile.Boundary do
           "(references from #{inspect(error.from_boundary)} to #{inspect(error.to_boundary)} are not allowed)"
       end
 
-    message = "forbidden reference to #{inspect(error.reference.to)}\n  #{reason}"
+    docs_link = "See https://hexdocs.pm/boundary/Mix.Tasks.Compile.Boundary.html for details."
+    message = "forbidden reference to #{inspect(error.reference.to)}\n  #{reason}\n  #{docs_link}"
 
     diagnostic(message, file: Path.relative_to_cwd(error.reference.file), position: error.reference.line)
   end