Add guides (#224)

* Add guides

* Add versioning to guides

* Guides: special variables and nested expressions

* Add guides page to vite build

* Add search and hash hooks, guide tags and headings

* Improve guides list and filtering

* Add 1.19 download link

src/app/hooks/useHash.ts

@@ -0,0 +1,27 @@
+import { useCallback, useEffect, useState } from 'preact/hooks'
+import { changeUrl } from '../Utils'
+
+export function useHash(): [string, (hash: string) => unknown] {
+	const [hash, setHash] = useState(window.location.hash)
+
+	const onChange = useCallback(() => {
+		setHash(window.location.hash)
+	}, [])
+
+	useEffect(() => {
+		window.addEventListener('hashchange', onChange)
+		window.addEventListener('replacestate', onChange)
+		return () => {
+			window.removeEventListener('hashchange', onChange)
+			window.removeEventListener('replacestate', onChange)
+		}
+	}, [])
+
+	const changeHash = useCallback((newHash: string) => {
+		if (newHash !== hash) {
+			changeUrl({ hash: newHash })
+		}
+	}, [hash])
+
+	return [hash, changeHash]
+}