Update to reveal.js 4.6.1

Change-Id: I566737c50b93dd8c094ad3c3fa59865260b3b4ba
diff --git a/inst/reveal.js-4.6.1/.github/workflows/js.yml b/inst/reveal.js-4.6.1/.github/workflows/js.yml
new file mode 100644
index 0000000..af86bea
--- /dev/null
+++ b/inst/reveal.js-4.6.1/.github/workflows/js.yml
@@ -0,0 +1,27 @@
+name: tests
+
+on: [push]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [14.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm run build --if-present
+    - run: npm test
+      env:
+        CI: true