move Peered to implementation directory

Implementation/Peered/SetUsername/SetUserNameBottomSheetView.swift

@@ -0,0 +1,19 @@
+import SwiftUI
+
+struct SetUserNameBottomSheetView: View {
+  @State private var proposedUsername: String = ""
+  @Binding var username: String
+
+  var body: some View {
+    Form {
+      Section("Set your username") {
+        TextField("Username", text: $proposedUsername)
+      }
+
+      Button("Save username") {
+        username = proposedUsername
+      }
+    }
+    .interactiveDismissDisabled()
+  }
+}