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/api/store/readme.mdx

@@ -0,0 +1,22 @@
+---
+title: Store
+---
+
+A **Store** object holds a simple key/value store with methods for storing and
+retrieving data. It is shared across the pattern, and is the recommended way
+to pass data between your parts.
+
+## Methods and Properties
+
+A Store object exposes the following methods and properties:
+
+<ReadMore recurse />
+
+## Extended store methods
+
+The store can also be extended with additional methods by plugins.
+
+- Refer to [the Store Methods documentation](/reference/store-methods)
+for more information and a list of store methods maintained by FreeSewing.
+- Refer to [the Plugin guide](/guides/plugins) for information about how
+plugins can be used to provide store methods.