Merge pull request #6 from haya14busa/readme

Readme

README.md

@@ -5,3 +5,66 @@
 [![reviewdog](https://github.com/haya14busa/action-docker-template/workflows/reviewdog/badge.svg)](https://github.com/haya14busa/action-docker-template/actions?query=workflow%3Areviewdog)
 [![release](https://github.com/haya14busa/action-docker-template/workflows/release/badge.svg)](https://github.com/haya14busa/action-docker-template/actions?query=workflow%3Arelease)
 [![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/haya14busa/action-docker-template?logo=github&sort=semver)](https://github.com/haya14busa/action-docker-template/releases)
+
+This is a template repository for [creating a Docker container action](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-a-docker-container-action).
+with release automation and [reviewdog](https://github.com/reviewdog/reviewdog) (linters) integrations.
+Click `Use this template` button to create your action based on this template.
+
+A sample action is to get GitHub star counts from a given repository.
+
+## Input
+<!-- TODO: update -->
+
+```yaml
+inputs:
+  github_token:
+    description: 'GITHUB_TOKEN'
+    default: '${{ github.token }}'
+  repo:
+    description: 'target GitHub repository. e.g. reviewdog/reviewdog'
+    default: '${{ github.repository }}'
+    required: true
+```
+
+## Usage
+<!-- TODO: update -->
+
+```yaml
+- name: Get Star Count
+  uses: haya14busa/action-docker-template@v1
+  id: sample
+  with:
+    repo: "reviewdog/reviewdog"
+
+- name: Check Star Count
+  run: |
+    echo "${{ steps.sample.outputs.star }}"
+```
+
+## Development
+
+### Release
+
+#### [haya14busa/action-bumpr](https://github.com/haya14busa/action-bumpr)
+You can bump version on merging Pull Requests with specific labels (bump:major,bump:minor,bump:patch).
+Pushing tag manually by yourself also work.
+
+#### [haya14busa/action-update-semver](https://github.com/haya14busa/action-update-semver)
+
+This action updates major/minor release tags on a tag push. e.g. Update v1 and v1.2 tag when released v1.2.3.
+ref: https://help.github.com/en/articles/about-actions#versioning-your-action
+
+### Lint - reviewdog integration
+
+![reviewdog integration](https://user-images.githubusercontent.com/3797062/72735107-7fbb9600-3bde-11ea-8087-12af76e7ee6f.png)
+
+Supported linters:
+
+- [reviewdog/action-shellcheck](https://github.com/reviewdog/action-shellcheck)
+- [reviewdog/action-hadolint](https://github.com/reviewdog/action-hadolint)
+- [reviewdog/action-misspell](https://github.com/reviewdog/action-misspell)
+
+### Dependencies Update Automation
+This template repository doesn't have dependencies, but you can use
+[haya14busa/action-depup](https://github.com/haya14busa/action-depup) to update
+dependencies in plain text format automatically.