feat: Translate frontend/src/i18n/en.json in bg

78% of minimum 50% translated source file: 'frontend/src/i18n/en.json'
on 'bg'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

frontend/src/i18n/bg.json

@@ -209,7 +209,7 @@
     "perm": {
       "create": "Създаване на файлове и директорий",
       "delete": "Изтриване на файлове и директорий",
-      "download": "Download",
+      "download": "Сваляне",
       "execute": "Execute commands",
       "modify": "Edit files",
       "rename": "Rename or move files and directories",