chore: add missing documentation, hide private (#62)

Adds some missing documentation and typespecs. Hides implementation
details from the docs

Author: davydog187

lib/openid_connect.ex

@@ -330,6 +330,12 @@ defmodule OpenIDConnect do
   defp audience_matches?(aud, expected_aud) when is_list(aud), do: Enum.member?(aud, expected_aud)
   defp audience_matches?(aud, expected_aud), do: aud === expected_aud
 
+  @doc """
+  Fetch claims about the authenticated end-user
+
+  For more information, see the [OpenID Connect Spec](https://openid.net/specs/openid-connect-core-1_0.html#UserInfo)
+  """
+  @spec fetch_userinfo(config(), jwt()) :: {:ok, response :: map()} | {:error, term()}
   def fetch_userinfo(config, access_token) do
     discovery_document_uri = config.discovery_document_uri
 

lib/openid_connect/application.ex

@@ -1,4 +1,5 @@
 defmodule OpenIDConnect.Application do
+  @moduledoc false
   use Application
 
   def start(_type, _args) do

lib/openid_connect/document.ex

@@ -14,12 +14,18 @@ defmodule OpenIDConnect.Document do
             jwks: nil,
             expires_at: nil
 
+  @type t :: %__MODULE__{}
+
   @refresh_time_seconds Application.compile_env(
                           :openid_connect,
                           :document_max_expiration_seconds,
                           60 * 60
                         )
 
+  @doc """
+  Fetches an OIDC document from cache, falling back to fetching from the remote resource
+  """
+  @spec fetch_document(String.t()) :: {:ok, t()} | {:error, term()}
   def fetch_document(uri) do
     with :error <- Cache.fetch(uri),
          {:ok, document_json, document_expires_at} <- fetch_remote_resource(uri),

lib/openid_connect/document/cache.ex

@@ -1,4 +1,5 @@
 defmodule OpenIDConnect.Document.Cache do
+  @moduledoc false
   use GenServer
   alias OpenIDConnect.Document