add CI workflow and scripts to rebuild search index

.github/workflows/deploy-docs.yml

@@ -4,8 +4,8 @@ on:
 permissions: read-all
 jobs:
   build:
-    runs-on: ubuntu-latest
     #if: github.repository_owner == 'spring-projects'
+    runs-on: ubuntu-latest
     steps:
     - name: Checkout
       uses: actions/checkout@v2

.github/workflows/rebuild-search-index.yml

@@ -0,0 +1,15 @@
+name: Rebuild Search Index
+on:
+  workflow_dispatch:
+permissions: read-all
+jobs:
+  build:
+    #if: github.repository_owner == 'spring-projects'
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 5
+    - name: Run Docsearch Scraper
+      run: $GITHUB_WORKSPACE/.github/actions/algolia-docsearch-scraper.sh "${{ secrets.ALGOLIA_APPLICATION_ID }}" "${{ secrets.ALGOLIA_WRITE_API_KEY }}" $GITHUB_WORKSPACE/.github/actions/algolia-config.json