User Settings: Rename Experiments to Nostr

And use a nostr icon

app/controllers/settings_controller.rb

@@ -12,7 +12,7 @@ class SettingsController < ApplicationController
   end
 
   def show
-    if @settings_section == "experiments"
+    if @settings_section == "nostr"
       session[:shared_secret] ||= SecureRandom.base64(12)
     end
   end
@@ -120,7 +120,7 @@ class SettingsController < ApplicationController
   def remove_nostr_pubkey
     current_user.update! nostr_pubkey: nil
 
-    redirect_to setting_path(:experiments), flash: {
+    redirect_to setting_path(:nostr), flash: {
       success: 'Public key removed from account'
     }
   end
@@ -134,8 +134,8 @@ class SettingsController < ApplicationController
     def set_settings_section
       @settings_section = params[:section]
       allowed_sections = [
-        :profile, :account, :xmpp, :email, :lightning, :remotestorage,
-        :experiments
+        :profile, :account, :xmpp, :email,
+        :lightning, :remotestorage, :nostr
       ]
 
       unless allowed_sections.include?(@settings_section.to_sym)