Update docs

README.md

@@ -41,8 +41,9 @@ releases: [
 ]
 ```
 
-Or you can read the config path from a specified environment variable. Booting
-the application fails if the environment variable is undefined.
+Or you can read the config directory or path from a specified environment
+variable. Booting the application fails if the specified environment variable is
+undefined.
 
 ```elixir
 releases: [
@@ -56,6 +57,19 @@ releases: [
 ]
 ```
 
+Or:
+
+```elixir
+releases: [
+  my_app: [
+    config_providers: [
+      {TomlConfigProvider, path: {:system, "RELEASE_CONFIG_PATH"}}
+    ],
+    ...
+  ]
+]
+```
+
 All config provider options except `:path` are forwarded to `Toml.decode_file/2`
 from the [toml-elixir](https://github.com/bitwalker/toml-elixir) library. Thus,
 you can also provide custom transforms.

lib/toml_config_provider.ex

@@ -18,8 +18,9 @@ defmodule TomlConfigProvider do
         ]
       ]
 
-  Or you can read the config path from a specified environment variable. Booting
-  the application fails if the environment variable is undefined.
+  Or you can read the config directory or path from a specified environment
+  variable. Booting the application fails if the specified environment variable
+  is undefined.
 
       releases: [
         my_app: [
@@ -31,6 +32,17 @@ defmodule TomlConfigProvider do
         ]
       ]
 
+  Or:
+
+      releases: [
+        my_app: [
+          config_providers: [
+            {TomlConfigProvider, path: {:system, "RELEASE_CONFIG_PATH"}}
+          ],
+          ...
+        ]
+      ]
+
   All config provider options except `:path` are forwarded to
   `Toml.decode_file/2`. Thus, you can also provide custom transforms.
 
@@ -43,8 +55,6 @@ defmodule TomlConfigProvider do
 
   @behaviour Config.Provider
 
-  alias TomlConfigProvider.FileNotFoundError
-
   @impl true
   def init(opts), do: opts