fix: add doc & dialyzer fixes

Author: MikaAK

lib/cache/metrics.ex

@@ -1,7 +1,8 @@
 if Application.ensure_loaded(:prometheus_telemetry) === :ok do
   defmodule Cache.Metrics do
     @moduledoc """
-    Add the following metrics for elixir_cache:
+    Add the following metrics for elixir_cache into [prometheus_telmetery](https://hexdocs.pm/prometheus_telemetry),
+    this module will only be included if the library is included:
 
     Metrics included:
       - `elixir_cache.cache.get.count`

lib/cache/sandbox.ex

@@ -333,11 +333,11 @@ defmodule Cache.Sandbox do
     raise "Not Implemented"
   end
 
-  def smembers(_cache_name, _key, _opts \\ []) do
+  def smembers(_cache_name, _key, _opts) do
     raise "Not Implemented"
   end
 
-  def sadd(_cache_name, _key, _value, _opts \\ []) do
+  def sadd(_cache_name, _key, _value, _opts) do
     raise "Not Implemented"
   end
 

mix.exs

@@ -95,7 +95,7 @@ defmodule ElixirCache.MixProject do
         "Changelog": ["CHANGELOG.md"]
       ],
       groups_for_modules: [
-        "Main": [Cache],
+        "Main": [Cache, Cache.Metrics],
 
         "Adapters": [
           Cache.Agent,
@@ -110,10 +110,7 @@ defmodule ElixirCache.MixProject do
           Cache.SandboxRegistry
         ],
 
-        "Internal": [
-          Cache.TermEncoder,
-          Cache.Metrics
-        ]
+        "Internal": [Cache.TermEncoder]
       ]
     ]
   end