Thunderbird for Android: use Firefox for Android to edit and sign documents

[Philipp]

let pdf files open in Firefox for Android and send them via Thunderbird for Android once editing is finished.
(this feature depends on https://bugzilla.mozilla.org/show_bug.cgi?id=1988994)

[Jon]

Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.