Update: Use yarn 2 with pnp (coscine/issues#1227)

package.json

@@ -31,9 +31,13 @@
     "@semantic-release/npm": "^7.0.6",
     "@semantic-release/release-notes-generator": "^9.0.1",
     "@types/node": "^14.14.20",
+    "@typescript-eslint/eslint-plugin": "^4.12.0",
+    "@typescript-eslint/parser": "^4.12.0",
     "@vue/cli-plugin-typescript": "^4.5.7",
     "@vue/cli-service": "^4.5.7",
+    "conventional-changelog-eslint": "3.0.9",
     "core-js": "^3.8.2",
+    "eslint": "^7.17.0",
     "semantic-release": "^17.3.1",
     "typescript": "^4.0.3",
     "vue-template-compiler": "^2.6.12"