Project tree view and creation (#203)

* Implement creating and importing new projects

* Add downloading a zip of a project

* Project validation (WIP)

* Add project side panel, remove project pages

* Project file saving

* Add file tree actions to rename and delete

* Fix file creation auto focus

* Add button to save file from menu

* Add project creation

* Fix specificity on version switcher button

* Update default version to 1.19

* List project files by type, remember project and delete project

src/app/components/BtnLink.tsx

@@ -0,0 +1,21 @@
+import { Octicon } from '.'
+
+interface Props {
+	link?: string,
+	icon?: keyof typeof Octicon,
+	label?: string,
+	tooltip?: string,
+	tooltipLoc?: 'se' | 'sw' | 'nw',
+	swapped?: boolean,
+}
+export function BtnLink({ link, icon, label, tooltip, tooltipLoc, swapped }: Props) {
+	return <a {...link ? { href: link } : { disabled: true }} class={`btn btn-link${tooltip ? ` tooltipped tip-${tooltipLoc ?? 'sw'}` : ''}`} aria-label={tooltip}>
+		{swapped ? <>
+			{label && <span>{label}</span>}
+			{icon && Octicon[icon]}
+		</> : <>
+			{icon && Octicon[icon]}
+			{label && <span>{label}</span>}
+		</>}
+	</a>
+}