fixup! Add TorStrings module for localization

Bug 40701: Improve security warning when downloading a file
Add strings for new pane, flag deprecated strings

Bug 40701: fix capitalization of 'internet'

toolkit/torbutton/chrome/locale/en-US/torbutton.properties

@@ -32,7 +32,7 @@ torbutton.circuit_display.click_to_copy = Click to Copy
 torbutton.circuit_display.copied = Copied!
 # end
 
-# External app blocker
+# External app blocker strings used up to 12.0 - TODO: remove when 12.5 becomes stable:
 torbutton.popup.external.title = Download an external file type?
 torbutton.popup.external.app = Tor Browser cannot display this file. You will need to open it with another application.\n\n
 torbutton.popup.external.note = Some types of files can cause applications to connect to the Internet without using Tor.\n\n
@@ -41,6 +41,14 @@ torbutton.popup.launch = Download file
 torbutton.popup.cancel = Cancel
 torbutton.popup.dontask = Automatically download files from now on
 
+# Download pane warning
+torbutton.download.warning.title = Be careful opening downloads
+# %S will be a link to the Tails operating system website. With the content given by torbutton.download.warning.tails_brand_name
+torbutton.download.warning.description = Some files may connect to the internet when opened without using Tor. To be safe, open the files while offline or use a portable operating system like %S.
+# Locale name for Tails operating system.
+torbutton.download.warning.tails_brand_name = Tails
+torbutton.download.warning.dismiss = Got it
+
 # .Onion Page Info prompt.
 pageInfo_OnionEncryptionWithBitsAndProtocol=Connection Encrypted (Onion Service, %1$S, %2$S bit keys, %3$S)
 pageInfo_OnionEncryption=Connection Encrypted (Onion Service)