Restructure project directories (#333)

`/client/web` -> `/frontend`
`/client/cli` -> *delete for now*
`/client/native` -> *delete for now*
`/core/editor` -> `/editor`
`/core/document` -> `/graphene`
`/core/renderer` -> `/charcoal`
`/core/proc-macro` -> `/proc-macros` *(now plural)*

frontend/.eslintrc.js

@@ -0,0 +1,49 @@
+module.exports = {
+	root: true,
+	env: {
+		browser: true,
+		node: true,
+		es2020: true,
+	},
+	extends: ["plugin:vue/vue3-essential", "@vue/airbnb", "@vue/typescript/recommended", "plugin:prettier-vue/recommended", "prettier"],
+	parserOptions: {
+		ecmaVersion: 2020,
+	},
+	settings: {
+		"import/resolver": {
+			// `node` must be listed first!
+			node: {},
+			webpack: { config: require.resolve("@vue/cli-service/webpack.config.js") },
+		},
+		"prettier-vue": {
+			SFCBlocks: {
+				template: true,
+				style: true,
+			},
+		},
+	},
+	ignorePatterns: ["node_modules/", "dist/", "pkg/", "wasm/pkg/*", "!.*.js", "!.*.ts", "!.*.json"],
+	rules: {
+		indent: ["error", "tab", { SwitchCase: 1 }],
+		quotes: ["error", "double"],
+		"linebreak-style": ["error", "unix"],
+		"eol-last": ["error", "always"],
+		"no-console": process.env.NODE_ENV === "production" ? "warn" : "off",
+		"no-debugger": process.env.NODE_ENV === "production" ? "warn" : "off",
+		"no-param-reassign": ["error", { props: false }],
+		"import/prefer-default-export": "off",
+		"max-len": ["error", { code: 200, tabWidth: 4 }],
+		"@typescript-eslint/camelcase": "off",
+		"@typescript-eslint/no-use-before-define": "off",
+		"@typescript-eslint/no-unused-vars": ["error", { argsIgnorePattern: "^_" }],
+		camelcase: ["error", { allow: ["^(?:[a-z]+_)*[a-z]+$"] }],
+		"prettier-vue/prettier": [
+			"error",
+			{
+				tabWidth: 4,
+				tabs: true,
+				printWidth: 200,
+			},
+		],
+	},
+};