Added new option for Copper (Joplin clone)

content/projects/copper.md

@@ -1,6 +1,7 @@
 +++
 title = "Radioactive Jagged Copper"
 date = 2020-11-04
+updated = 2021-01-04
 
 [taxonomies]
 tags = ["projects", "personal", "joplin"]
@@ -10,3 +11,8 @@ Rust Joplin Clone.
 
 Probably write something in Gtk-Rs (or similar) using the same format as
 Joplin, so their clients can be used for the same data.
+
+Options for frontend:
+
+- [Gtk-ts](https://gtk-rs.org/)
+- [Druid](https://github.com/linebender/druid)