Add help dialog with keybindings reference

components/help.js

@@ -0,0 +1,36 @@
+import { html, Component } from "../lib/index.js";
+import { keybindings } from "../keybindings.js";
+
+function KeyBindingsHelp() {
+	var l = keybindings.map((binding) => {
+		var keys = [];
+		if (binding.ctrlKey) {
+			keys.psuh("Ctrl");
+		}
+		if (binding.altKey) {
+			keys.push("Alt");
+		}
+		keys.push(binding.key);
+
+		keys = keys.map((name, i) => {
+			return html`
+				${i > 0 ? "+" : null}
+				<kbd>${name}</kbd>
+			`;
+		});
+
+		return html`
+			<dt>${keys}</dt>
+			<dd>${binding.description}</dd>
+		`;
+	});
+
+	return html`<dl>${l}</dl>`;
+}
+
+export default function Help() {
+	return html`
+		<h3>Key bindings</h3>
+		<${KeyBindingsHelp}/>
+	`;
+}