Add auto-updating CHANGELOG.md on develop branch

* Using the matrix function of Github actions, both develop and main branches will be applied automatically.

Resolves fosslight#57

Signed-off-by: riyenas0925 <riyenas0925@gmail.com>

.github/workflows/release-publish.yml

@@ -10,8 +10,13 @@ on:
 jobs:
   update-changelog:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ref: [main, develop]
     steps:
     - uses: actions/checkout@v2
+      with:
+        ref: ${{ matrix.ref }}
     - name: update changelog with gren
       env:
         GREN_GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -27,7 +32,7 @@ jobs:
       uses: ad-m/github-push-action@master
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
-        branch: main
+        branch: ${{ matrix.ref }}
   build:
     needs: update-changelog
     runs-on: ubuntu-18.04