docs: base plugin documentation

README.md

@@ -1,3 +1,29 @@
 # hermione-oauth
 
-Plugin for convenient setting of authorization header with OAuth token
+Some Remote WebDriver Servers requires OAuth authorization for each request. This plugin is useful for setting of authorization header with OAuth token.
+
+## Install
+
+```bash
+npm install hermione-oauth --save-dev
+```
+
+## Usage
+
+```js
+// .hermione.conf.js
+module.exports = {
+    // ...
+    plugins: {
+        "hermione-oauth": {
+            enabled: true, // plugin is enabled by default
+            token: "<token>", // option also accepts absolute filepath with a token
+            help: "https://...", // information on where to get a token
+        },
+    },
+};
+```
+
+Each plugin option can be redefined by
+- environment variable which starts with prefix `hermione_oauth_`, for example, `hermione_oauth_token=123-456-789`
+- CLI option which starts with prefix `--oauth-`, for example, `--oauth-token=123-456-789`