chore: Port FreeSewing.dev to docusaurus

The replaces the NextJS site powering FreeSewing.dev with a Docusaurus
setup. It's part of my efforts to simplify FreeSewing's setup so we can
focus on our core value proposition.

sites/dev/docs/reference/plugins/gore/readme.mdx

@@ -0,0 +1,32 @@
+---
+title: plugin-gore
+---
+
+Published as [@freesewing/plugin-gore][1], this plugin provides [the gore
+macro](/reference/macros/gore) which allows you to generate [gore
+segments](https://en.wikipedia.org/wiki/Gore_\(segment\)); 2D panels to create
+a spherical shape as used in hats for example.
+
+This plugin handles all the mathematics to create a (part-)sphere in your
+designs.
+
+## Installation
+
+```sh
+npm install @freesewing/plugin-gore
+```
+
+## Usage
+
+Either [add it as a part plugins](/reference/api/part/config/plugins) in your
+design, or [add it to a pattern instance with
+Pattern.use()](/reference/api/pattern/use).
+
+To import the plugin for use:
+```js
+import { gorePlugin } from '@freesewing/plugin-gore'
+// or
+import { pluginGore } from '@freesewing/plugin-gore'
+```
+
+[1]: https://www.npmjs.com/package/@freesewing/plugin-gore