Bump moment from 2.12.0 to 2.29.4 in /generator-exercise

Bumps [moment](https://github.com/moment/moment) from 2.12.0 to 2.29.4.
- [Release notes](https://github.com/moment/moment/releases)
- [Changelog](https://github.com/moment/moment/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/moment/moment/compare/2.12.0...2.29.4)

---
updated-dependencies:
- dependency-name: moment
  dependency-type: indirect
...

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

generator-exercise/package-lock.json

@@ -3226,6 +3226,12 @@
         }
       }
     },
+    "moment": {
+      "version": "2.29.4",
+      "resolved": "https://registry.npmjs.org/moment/-/moment-2.29.4.tgz",
+      "integrity": "sha512-5LC9SOxjSc2HF6vO2CyuTDNivEdoz2IvyJJGj6X8DJ0eFyfszE0QiEd+iXmBvUP3WHxSjFH/vIsA0EN00cgr8w==",
+      "dev": true
+    },
     "ms": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
@@ -3490,12 +3496,6 @@
               "integrity": "sha1-vgPfjMPineTSxd9lASY/H6RZXpo=",
               "dev": true
             },
-            "moment": {
-              "version": "2.12.0",
-              "resolved": "https://registry.npmjs.org/moment/-/moment-2.12.0.tgz",
-              "integrity": "sha1-3CVg0Zg41sBzGxpq+gRnUmTTYNY=",
-              "dev": true
-            },
             "topo": {
               "version": "1.1.0",
               "resolved": "https://registry.npmjs.org/topo/-/topo-1.1.0.tgz",