Allow multiple errors and dismissing errors

src/app/components/ErrorPanel.tsx

@@ -1,5 +1,12 @@
-export function ErrorPanel({ error }: { error: string }) {
+import { Octicon } from './Octicon'
+
+type ErrorPanelProps = {
+	error: string,
+	onDismiss?: () => unknown,
+}
+export function ErrorPanel({ error, onDismiss }: ErrorPanelProps) {
 	return <div class="error">
+		{onDismiss && <div class="error-dismiss" onClick={onDismiss}>{Octicon.x}</div>}
 		<h3>{error}</h3>
 		<p>You can report this as a bug <a href="https://github.com/misode/misode.github.io/issues/new" target="_blank">on GitHub</a></p>
 	</div>