feat: add support for NIP-29 (#56)

Reviewed-on: #56

crates/workspace/src/dialogs/join_group.rs

@@ -0,0 +1,35 @@
+use gpui::{App, AppContext, ParentElement, Styled, Window, px};
+use nip29::{GroupReference, GroupsRegistry};
+use ui::WindowExtension;
+use ui::input::{Input, InputState};
+use ui::notification::Notification;
+
+pub fn open(window: &mut Window, cx: &mut App) {
+    let input = cx.new(|cx| InputState::new(window, cx).placeholder("naddr1…"));
+
+    window.open_dialog(cx, move |this, _window, _cx| {
+        let input = input.clone();
+
+        this.width(px(380.))
+            .confirm()
+            .title("Join Group")
+            .child(Input::new(&input).cleanable(true).flex_1().text_sm())
+            .on_ok(move |_event, window, cx| {
+                let groups = GroupsRegistry::global(cx);
+
+                let reference = match GroupReference::parse(input.read(cx).value().trim()) {
+                    Ok(reference) => reference,
+                    Err(error) => {
+                        window.push_notification(Notification::error(error.to_string()), cx);
+                        return false;
+                    }
+                };
+
+                groups.update(cx, |registry, cx| {
+                    registry.join(reference, cx);
+                });
+
+                true
+            })
+    });
+}