docs(README): update

Author: exuanbo

README.md

@@ -23,28 +23,32 @@ This is a Github Action to deploy your file to Github Gist.
 
 ### Prep work
 
-1. Create a public gist if you don't have one.
+1. Create a gist (public or secret) if you don't have one.
 1. Generate a new [Personal access token](https://github.com/settings/tokens/). Only the `gist` scope is needed. Check [Scopes for OAuth Apps](https://docs.github.com/en/developers/apps/scopes-for-oauth-apps) for details.
 
 ### Project setup
 
-1. Go to the repo **Settings > Secrets**. Add the generated token as `TOKEN`.
+1. Go to the repo **Settings > Secrets**. Add the generated token with name `TOKEN`.
 1. Edit workflow file `.github/workflows/deploy.yml` as the example above.
 
 ### Options
 
+#### `token`
+
+The personal access token for updating gist.
+
 #### `gist_id`
 
 The id portion from your gist url, e.g. `https://gist.github.com/exuanbo/`**`e885afa349a0e5d1cfb408e46d6a37bc`**.
 
-#### `gist_file_name`
+#### `gist_file_name` (optional)
 
-Name of the file to be added in your gist. If not provided, the original file name from `file_path` will be used.
+The name of the file to be added in your gist. If not provided, the original file name from `file_path` will be used.
 
 #### `file_path`
 
 Relative to your repo's root directory, e.g. `./dist/foo.bar`.
 
 ## License
 
-[MIT](https://github.com/exuanbo/actions-deploy-gist/blob/main/LICENSE)
+[MIT License](https://github.com/exuanbo/actions-deploy-gist/blob/main/LICENSE) © 2021 [Exuanbo](https://github.com/exuanbo)