docs: add branches alpha and beta

Author: luthfimasruri

.github/workflows/deploy-docs.yml

@@ -4,6 +4,8 @@ on:
   push: 
     branches: 
       - master
+      - beta
+      - alpha
     paths:
       - 'docs/**'
 
@@ -12,7 +14,7 @@ jobs:
     name: Build and deploy
     runs-on: ubuntu-latest
     steps: 
-      - uses: actions/checkout@master
+      - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with: 
           node-version: '14.x'