Add docs updater workflow

This updates the repo to push changes in the documentation content to
docs.styra.com. STYRA_DOCS_DEPLOY_KEY must be set in the repo secrets
before this will work.

Signed-off-by: Charlie Egan <charlieegan3@users.noreply.github.com>

.github/workflows/update-docs.yaml

@@ -0,0 +1,32 @@
+# this workflow is used to update the content at docs.styra.com
+# when it changes in this repo.
+name: Update Docs
+
+on:
+  push:
+    branches:
+    - main
+  workflow_dispatch:
+
+jobs:
+  update-docs:
+    name: Update Docs
+    runs-on: ubuntu-22.04
+    steps:
+    - name: Check out code
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      with:
+        fetch-depth: 0
+
+    - name: Save version
+      run: |
+        mkdir -p versions
+        echo "${{ github.sha }}" > versions/lib.jwt
+
+    - name: Update docs
+      uses: leigholiver/commit-with-deploy-key@9562ffd1c0965c6d4f264e2555a569bd33ac7d05
+      with:
+        source: versions
+        destination_folder: imported/versions
+        destination_repo: StyraInc/docs
+        deploy_key: ${{ secrets.STYRA_DOCS_DEPLOY_KEY }}