add doc for validate!/1 and validate/1

Author: vacarsu

lib/scenic/themes.ex

@@ -111,6 +111,9 @@ defmodule Scenic.Themes do
     end
   end
 
+  @doc """
+  Validates a theme, raises when an invalid themes is passed in.
+  """
   def validate!(theme)
   def validate!({lib, theme_name} = lib_theme) when is_atom(theme_name) do
     themes = module().library()
@@ -256,6 +259,9 @@ defmodule Scenic.Themes do
     end)
   end
 
+  @doc """
+  Validates a theme, returns `{:ok, theme}` on a valid theme or `{:error, :error_type}` on an invalid theme.
+  """
   def validate(theme)
   def validate({lib, theme_name} = lib_theme) when is_atom(theme_name) do
     themes = module().library()
@@ -318,22 +324,22 @@ defmodule Scenic.Themes do
       _, {:error, msg} ->
         {:error, msg}
 
-      {key, color}, {:ok, _} = acc ->
+      {_key, color}, {:ok, _} = acc ->
         case Color.validate(color) do
           {:ok, _} -> acc
-          {:error, msg} -> {:error, :invalid_color}
+          {:error, _msg} -> {:error, :invalid_color}
         end
     end)
   end
 
-  def validate(%{} = map) do
+  def validate(%{} = _map) do
     {
       :error,
       :missing_key
     }
   end
 
-  def validate(data) do
+  def validate(_data) do
     {
       :error,
       :invalid