Open a GitHub Issue if vulnerabilities are found (#8)

* Get GitHub access token from input

* install npm package

* fix TypeScript error to successfully build

ref: https://github.com/actions/toolkit/issues/199

* npm i strip-ansi to remove control characters

* create an issue

* use template literal to pass lint

* npm run format; npm run lint

* use inputs.issue_title as issue title

* document inputs.issue_title

* add inputs.issue_title

README.md

@@ -1,3 +1,12 @@
 # npm audit action
 
 GitHub Action to run `npm audit`
+
+## Usage
+
+### Inputs
+
+|Parameter|Required|Default Value|Description|
+|:--:|:--:|:--:|:--|
+|issue_title|false|npm audit found vulnerabilities|Issue title|
+|token|true|N/A|GitHub Access Token.<br>${{ secrets.GITHUB_TOKEN }} is recommended.|