flake.lock: Updating 'revealjs (hakimel/reveal.js)' - 6b535328 -> ff200518 (#58)

### Changes for revealjs

On branch: master
Commits: 6b535328c0...ff20051861

- [ff200518](ff20051861) fiv out of sync speaker view after presentation reloads [hakimel/reveal.js⁠#2822](http://r.duckduckgo.com/l/?uddg=https://github.com/hakimel/reveal.js/issues/2822) [hakimel/reveal.js⁠#3032](http://r.duckduckgo.com/l/?uddg=https://github.com/hakimel/reveal.js/issues/3032)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

flake.lock

@@ -291,11 +291,11 @@
     "revealjs": {
       "flake": false,
       "locked": {
-        "lastModified": 1643789207,
-        "narHash": "sha256-b32w+oxjMH/or0Q5zFcrJ9UcDm8DFsow1nzZD8oETnw=",
+        "lastModified": 1644496127,
+        "narHash": "sha256-d3Rrqi2MAeme9Zwg8L+HEe7ch8gFEJ6XDjmo2xSxPO0=",
         "owner": "hakimel",
         "repo": "reveal.js",
-        "rev": "6b535328c0a9615c9cf4759acf81cd02f0516ba1",
+        "rev": "ff20051861f16da2f69fe9de8cc5dc54b2a79207",
         "type": "github"
       },
       "original": {