feat: Add Canva embed support

shared/editor/embeds/Canva.tsx

@@ -0,0 +1,22 @@
+import * as React from "react";
+import Frame from "../components/Frame";
+import { EmbedProps as Props } from ".";
+
+function Canva(props: Props) {
+  const { matches } = props.attrs;
+  const embedId = matches[1];
+
+  return (
+    <Frame
+      {...props}
+      src={`https://www.canva.com/design/${embedId}/view?embed`}
+      title="Canva"
+    />
+  );
+}
+
+Canva.ENABLED = [
+  /^https:\/\/(?:www\.)?canva\.com\/design\/([a-zA-Z0-9]*)\/(.*)$/,
+];
+
+export default Canva;