chore(deps): bump bootstrap from 4.4.1 to 5.0.0 in /css

Bumps [bootstrap](https://github.com/twbs/bootstrap) from 4.4.1 to 5.0.0.
- [Release notes](https://github.com/twbs/bootstrap/releases)
- [Commits](twbs/bootstrap@v4.4.1...v5.0.0)

---
updated-dependencies:
- dependency-name: bootstrap
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

css/package.json

@@ -4,7 +4,7 @@
   "description": "A reactive framework built on shiny.",
   "main": "dist/yonder.min.css",
   "dependencies": {
-    "bootstrap": "^4.4.1",
+    "bootstrap": "^5.0.0",
     "bs-custom-file-input": "^1.3.2",
     "jquery": "^3.4.1",
     "popper.js": "^1.16.0"