Add lint to CI and fix errors (#853)

Adds lint to CI and fixes errors.
I'm not sure I'm fully proud of all the solutions there.
But there's no lint issues and the lint is being checked as part of the
CI.

---------

Co-authored-by: Yuri Astrakhan <[email protected]>

.eslintrc

@@ -0,0 +1,45 @@
+{
+    "root": true,
+    "env": { 
+      "browser": true, 
+      "es2020": true 
+    },
+    "extends": [
+      "eslint:recommended",
+      "plugin:react/recommended",
+      "plugin:react/jsx-runtime",
+      "plugin:react-hooks/recommended",
+    ],
+    "ignorePatterns": [
+      "dist"
+    ],
+    "parser": "@typescript-eslint/parser",
+    "parserOptions": { 
+      "ecmaVersion": "latest", 
+      "sourceType": "module" 
+    },
+    "settings": { 
+      "react": { "version": "16.4" } 
+    },
+    "plugins": [
+      "@typescript-eslint",
+      "react-refresh"],
+    "rules": {
+      "react-refresh/only-export-components": [
+        "warn",
+        { "allowConstantExport": true }
+      ],
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        { "argsIgnorePattern": "^_" }
+      ],
+      "no-unused-vars": "off",
+      "react/prop-types": ["off"],
+      // Disable no-undef. It's covered by @typescript-eslint
+      "no-undef": "off",
+      "indent": ["error", 2]
+    },
+    "globals": {
+      "global": "readonly"
+  }
+}

.github/workflows/ci.yml

@@ -42,6 +42,9 @@ jobs:
           ${{ runner.os }}-node-
     - run: npm ci
     - run: npm run build
+    - run: npm run lint
+    - run: npm run lint-css
+
 
 
   build-artifacts: