Add docs for plugin-bugfix-safari-class-field-initializer-scope

See babel/babel#16569

Doc structure adapted from `plugin-bugfix-firefox-class-in-computed-class-key`

docs/plugin-bugfix-safari-class-field-initializer-scope.md

@@ -0,0 +1,41 @@
+---
+id: babel-plugin-bugfix-safari-class-field-initializer-scope
+title: "@babel/plugin-bugfix-safari-class-field-initializer-scope"
+sidebar_label: bugfix-safari-class-field-initializer-scope
+---
+
+This bugfix plugin wraps some class field initializers with an IIFE to workaround [a WebKit bug](https://webkit.org/b/236843) which affects Safari 15.
+
+:::tip
+This plugin is included in `@babel/preset-env`, and Babel will automatically enable this plugin for you when your `targets` are affected by the browser bug.
+:::
+
+## Installation
+
+```shell npm2yarn
+npm install --save-dev @babel/plugin-bugfix-safari-class-field-initializer-scope
+```
+
+## Usage
+
+### With a configuration file (Recommended)
+
+```json title="babel.config.json"
+{
+  "plugins": ["@babel/plugin-bugfix-safari-class-field-initializer-scope"]
+}
+```
+
+### Via CLI
+
+```sh title="Shell"
+babel --plugins @babel/plugin-bugfix-safari-class-field-initializer-scope script.js
+```
+
+### Via Node API
+
+```js title="JavaScript"
+require("@babel/core").transformSync("code", {
+  plugins: ["@babel/plugin-bugfix-safari-class-field-initializer-scope"],
+});
+```