feat: Docusaurus ESLint plugin to enforce best Docusaurus practices (#7206)

* feat: add eslint plugin

* refactor

* add tests

* fixups!

* fix(no-dynamic-i18n-messages): make translate() recognize template literals

* refactor: rename rule no-dynamic-i18n-messages --> string-literal-i18n-messages

* feat: add ignoreStrings option and refactor

* docs: migrate docs to /docs/api/plugins

* docs: fix anchor links in README.md

* fix: add some ignored strings

* docs: update eslint-plugin docs

* fix: update README link

* docs: various updates

- Reorder sidebar entries
- Fix title size
- Use Markdown file paths
- Simplify relative links

* address reviews

* wording polish

* add npmignore

* fix all internal warnings

* doc improvements

* fix test

Co-authored-by: Joshua Chen <sidachen2003@gmail.com>

packages/eslint-plugin/lib/index.js

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const requireIndex = require('requireindex');
+
+module.exports = {
+  rules: requireIndex(`${__dirname}/rules`),
+  configs: {
+    recommended: {
+      rules: {
+        '@docusaurus/string-literal-i18n-messages': 'error',
+      },
+    },
+    all: {
+      rules: {
+        '@docusaurus/string-literal-i18n-messages': 'error',
+        '@docusaurus/no-untranslated-text': 'warn',
+      },
+    },
+  },
+};