Pontoon: Update Bulgarian (bg) localization of Facebook Container

Co-authored-by: :stoyan <stoyan@gmx.com>
Co-authored-by: Teodor P. <teo0321@gmail.com>

src/_locales/bg/messages.json

@@ -3,8 +3,36 @@
     "message": "Facebook Container",
     "description": "This is the name of the extension, and appears at the top of all onboarding panels. Please do not translate \"Facebook Container\"."
   },
+  "onboarding1-subhead": {
+    "message": "Използване на Facebook Container",
+    "description": "This is the subhead of onboarding panel 1. Please do not translate \"Facebook Container\""
+  },
+  "btn-cancel": {
+    "message": "Отказ",
+    "description": "This is a button to cancel out of the onboarding panel."
+  },
+  "btn-next": {
+    "message": "Напред",
+    "description": "This is a button to continue to the next onboarding panel."
+  },
+  "btn-back": {
+    "message": "Назад",
+    "description": "This is a button that returns the user to the previous onboarding panel."
+  },
+  "btn-done": {
+    "message": "Готово",
+    "description": "This is a button the user clicks to close out the panel when they have finished reading the text."
+  },
+  "btn-arrow-back": {
+    "message": "Назад към предишен панел.",
+    "description": "This is alternative text for the back arrow button."
+  },
   "learn-more": {
     "message": "Научете повече",
     "description": "This is a link that opens a page with more information about Facebook Container."
+  },
+  "inPageUI-tooltip-prompt-checkbox": {
+    "message": "Спиране на този въпрос",
+    "description": ""
   }
 }