Make eslint work, and fix all warnings. (#511)

* Make eslint work, and fix all warnings.

* Don't ignore v-html rule globally.

* Remove eslint file and merge in package.json.

package.json

@@ -34,6 +34,8 @@
         "@vue/compiler-sfc": "3.2.19",
         "babel-eslint": "^10.1.0",
         "eslint": "^7.32.0",
+        "eslint-config-prettier": "^8.3.0",
+        "eslint-plugin-prettier": "^4.0.0",
         "eslint-plugin-vue": "^7.19.1"
     },
     "eslintConfig": {
@@ -43,6 +45,7 @@
         },
         "extends": [
             "plugin:vue/vue3-essential",
+            "plugin:prettier/recommended",
             "eslint:recommended"
         ],
         "parserOptions": {