Tweak and re-organize ESLint config (#38369)

* Tweak and re-organize ESLint config

* merge individual configs to the root config
* enable more eslint-plugin-import rules
* lint markdown files

* Lint

build/.eslintrc.json

@@ -1,15 +0,0 @@
-{
-  "env": {
-    "browser": false,
-    "node": true
-  },
-  "parserOptions": {
-    "sourceType": "script"
-  },
-  "extends": "../.eslintrc.json",
-  "rules": {
-    "no-console": "off",
-    "strict": "error",
-    "unicorn/prefer-top-level-await": "off"
-  }
-}

build/banner.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const pkg = require('../package.json')
+
 const year = new Date().getFullYear()
 
 function getBanner(pluginFilename) {