Bump handlebars from 4.7.4 to 4.7.7

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.7.4 to 4.7.7.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md)
- [Commits](handlebars-lang/handlebars.js@v4.7.4...v4.7.7)

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

package.json

@@ -28,7 +28,7 @@
     "eslint": "^6.7.2",
     "eslint-config-prettier": "^6.7.0",
     "eslint-plugin-prettier": "^3.1.1",
-    "handlebars": "4.7.4",
+    "handlebars": "4.7.7",
     "http-server": "0.12.3",
     "marked": "0.8.2",
     "nodemon": "2.0.4",