Merge pull request #19 from simplybusiness/github-app-doc

Documentation for github app installation

README.md

@@ -8,8 +8,22 @@ Currently it supports bumping version for a gem.
 ## Bump version
 
 ### Installation
+Dobby requires a Github App to be installed either on an individual repository or organization wide. If you have already created a Github App you can follow instruction from step 3. Otherwise follow these steps: 
 
-Add a file to your github workflow `.github/workflows/dobby-action.yml` with following content:
+1. [Create a minimal GitHub App](https://docs.github.com/en/developers/apps/creating-a-github-app), setting the following fields:
+   - Set GitHub App name. 
+   - Set Homepage URL to your github repository.
+   - Uncheck Active under Webhook. You do not need to enter a Webhook URL.
+   - Under Repository permissions: Contents select Access: Read & write.
+   - Under Repository permissions: Pull requests select Access: Read & write. 
+
+2. Create a Private key from the App settings page and store it securely.
+
+3. Install the App either on your repository or organization wide.
+
+4. Set secrets on your repository or organization containing the GitHub App ID, and the private key you created in step 2 as DOBBY_APP_ID, DOBBY_PRIVATE_KEY
+
+5. Add a file to your github workflow `.github/workflows/dobby-action.yml` with following content:
 
 ```yaml
 
@@ -23,10 +37,11 @@ jobs:
     if: startsWith(github.event.comment.body, '/dobby')
 
     steps:
-      - name: 'bump version' 
-        uses: simplybusiness/dobby@v1.0.0
+      - name: bump version
+        uses: simplybusiness/dobby@v2.0.0
         env:
-          ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          DOBBY_APP_ID: ${{ secrets.DOBBY_APP_ID }}
+          DOBBY_PRIVATE_KEY: ${{ secrets.DOBBY_PRIVATE_KEY }}
           # Change to the file path where you keep the Gem's version.
           # It is usually `lib/<gem name>/version.rb` or in the gemspec file.
           VERSION_FILE_PATH: <VERSION FILE PATH>
@@ -47,4 +62,3 @@ where semver level can be minor/major/patch.
 2. You can see bot will add a comment on Pull request.
    
    ![Version update comment](docs/images/version-update.png)
-