feat: intro page (#416)

Fixes #415

lib/l10n/app_en.arb

@@ -101,6 +101,7 @@
   "export": "Export",
   "extraArgs": "Extra args",
   "failed": "Failed",
+  "fdroidReleaseTip": "If you downloaded this app from Fdroid, it is recommended to turn off this option.",
   "feedback": "Feedback",
   "feedbackOnGithub": "If you have any questions, please feedback on Github.",
   "fieldMustNotEmpty": "These fields must not be empty.",
@@ -135,6 +136,7 @@
   "imagesList": "Images list",
   "import": "Import",
   "inAppUpdate": "Update within the app? Otherwise, download using a browser.",
+  "init": "Initialize",
   "inner": "Inner",
   "inputDomainHere": "Input Domain here",
   "install": "install",