feat: demo deployment action (#30)

New GitHub Action that will build and push our demo.

## Demo patch

A patch containing all changes between develop and the
current demo branch has been generated:
```
$ git diff develop..demo --binary > algolia-demo.patch
```

## Workflow

The GitHub Action will:
- Checkout the `develop` branch (`${{ github.ref_name }}` points on the
branch that triggered the workflow
([doc](https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/store-information-in-variables#default-environment-variables)))
- Generate the `algolia-config.json` and `commerce-api-config.json`
files using `jq` to inject variables and secrets from env vars (c.f. [jq
doc](https://jqlang.github.io/jq/manual/#$env-env)).
- Apply the `algolia-demo.patch`
- Build and push the bundle

---
SFCC-384

.github/workflows/deploy-demo.yml

@@ -0,0 +1,38 @@
+name: Deploy demo
+
+on:
+  workflow_dispatch:
+#  push:
+#    branches: [ "develop" ]
+
+jobs:
+  deploy_demo:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.ref_name }}
+      - name: Generate algolia-config.json
+        env:
+          ALGOLIA_APP_ID: ${{ vars.ALGOLIA_APP_ID }}
+          ALGOLIA_API_KEY: ${{ vars.ALGOLIA_API_KEY }}
+        run: |
+          jq '.appId = env.ALGOLIA_APP_ID | .apiKey = env.ALGOLIA_API_KEY' config/algolia-config.example.json > config/algolia-config.json
+      - name: Generate commerce-api-config.json
+        env:
+          SFCC_SLAS_CLIENT_ID: ${{ secrets.SFCC_SLAS_CLIENT_ID }}
+          SFCC_ORGANIZATION_ID: ${{ vars.SFCC_ORGANIZATION_ID }}
+          SFCC_SHORT_CODE: ${{ vars.SFCC_SHORT_CODE }}
+          SFCC_SITE_ID: ${{ vars.SFCC_SITE_ID }}
+        run: |
+          jq '.clientId = env.SFCC_SLAS_CLIENT_ID
+          | .organizationId = env.SFCC_ORGANIZATION_ID
+          | .shortCode = env.SFCC_SHORT_CODE
+          | .siteId = env.SFCC_SITE_ID' config/commerce-api-config.example.json > config/commerce-api-config.json
+      - run: git apply algolia-demo.patch
+      - run: npm install
+      - name: Build and push to Managed Runtime
+        env:
+          MRT_USER: ${{ vars.MRT_USER }}
+          MRT_API_KEY: ${{ secrets.MRT_API_KEY }}
+        run: npm run push

.gitignore

@@ -1,4 +1,7 @@
-node_modules
-build
+.idea/
+
+node_modules/
+build/
+
 algolia-config.json
-commerce-api-config.json
+commerce-api-config.json