button tweaks

src/public/app/widgets/buttons/show_note_source.js

@@ -0,0 +1,16 @@
+import ButtonWidget from "./button_widget.js";
+
+export default class ShowNoteSourceButton extends ButtonWidget {
+    isEnabled() {
+        return super.isEnabled() && this.note && ['text', 'relation-map'].includes(this.note.type);
+    }
+
+    constructor() {
+        super();
+
+        this.icon('bx bx-code')
+            .title("Show Note Source")
+            .command("showNoteSource")
+            .titlePlacement("bottom");
+    }
+}