feat: init readme

Author: swimmwatch

README.md

@@ -0,0 +1,54 @@
+# webchanges-action
+A GitHub Action to detect web page changes. It uses [mborsetti/webchanges](https://github.com/mborsetti/webchanges) to find differences between web pages.
+
+## Usage
+
+The following example workflow step will create an issue in a GitHub repository if a web page has changed.
+
+```yml
+- name: "Detect web page changes"
+  id: webchanges
+  uses: swimmwatch/webchanges-action@v1.0.0
+  with:
+    jobs: |
+      name: Telegram Mini App documentation
+      url: https://core.telegram.org/bots/webapps
+      use_browser: false
+      filters:
+        - html2text
+    config: |
+      report:
+        tz: UTC
+        github_issue:
+          enabled: true
+          owner: '${{ github.repository_owner }}'
+          repo: '${{ github.event.repository.name }}'
+          token: '${{ secrets.GITHUB_TOKEN }}'
+          format_dt: '%Y-%m-%d'
+          title: 'Telegram Mini App documentation update {dt}'
+          assignees: 
+            - 'swimmwatch'
+          format_content: |
+            ```text
+            {content}
+            ```
+```
+
+## Options
+The following input variables options can/must be configured:
+
+| Input variable | Necessity | Description                                    | Default |
+|----------------|-----------|------------------------------------------------|---------|
+| `jobs`         | Required  | List of jobs to run for web changes detection. |         |
+| `config`       | Required  | Configuration for the web changes detector.    |         |
+
+
+## Contributing
+We love your input! We want to make contributing to this project as easy and transparent as possible, whether it's:
+- Reporting a bug
+- Discussing the current state of the code
+- Submitting a fix
+- Proposing new features
+
+## License
+webchanges-action is licensed under the [MIT License](LICENSE).