User Settings: Rename Experiments to Nostr

And use a nostr icon

spec/features/settings/nostr_spec.rb

@@ -1,6 +1,6 @@
 require 'rails_helper'
 
-RSpec.describe 'Experimental Settings', type: :feature do
+RSpec.describe 'Nostr Settings', type: :feature do
   let(:user) { create :user, cn: 'jimmy', ou: 'kosmos.org' }
 
   before do
@@ -9,7 +9,7 @@ RSpec.describe 'Experimental Settings', type: :feature do
 
   describe 'Adding a nostr pubkey' do
     scenario 'Without nostr browser extension available' do
-      visit setting_path(:experiments)
+      visit setting_path(:nostr)
       expect(page).to have_content("No browser extension found")
       expect(page).to have_css('button[data-settings--nostr-pubkey-target=setPubkey]:disabled')
     end
@@ -26,7 +26,7 @@ RSpec.describe 'Experimental Settings', type: :feature do
     end
 
     scenario 'Remove nostr pubkey from account' do
-      visit setting_path(:experiments)
+      visit setting_path(:nostr)
       expect(page).to have_field("nostr_public_key",
         with: "npub1qlsc3g0lsl8pw8230w8d9wm6xxcax3f6pkemz5measrmwfxjxteslf2hac",
         disabled: true)