Update backup and restore explanation & improve hindi, punjabi and assamese READMEs (#11243)

* update backup and restore explanation in punjabi README

* Update backup and restore explanation in hindi README

* add_matrix_link to hindi and punjabi README

also translate Warning in hindi & punjabi language Readme's

* improve hindi and punjabi readme

add missing link #supported-services in hindi readme (that is #समर्थित-सेवाएँ}
improve translation of supported services in punjabi
Use Fdroid Hindi badge instead of english in hindi readme

* revert translate Warning in hindi & punjabi language Readme's

* update backup and restore explanation in assamese README

* fix assamese readme librapay donate button not showing and fix weird formating

* add matrix chat link to assamese readme & fix Newpipe logo not showing

* Update Matrix room URL to new link

oh! I missed this one earlier

* remove references to Bitcoin and Bountysource donation options in hindi readme

* more improvements in punjabi README

* fix CONTRIBUTING.md link in punjabi readme

* fix CONTRIBUTING.md link in assamese readme

* add missing paragraphs in hindi translation for hi readme

* revert localisation of app name NewPipe as it stands out

* address the review and place supported-services at correct place in hindi readme

do required changes for punjabi
do much needed improvements in assamese readme

* fix formatting issues in assamese readme

* fix link to releases in punjabi readme

* resolve conflicts

Author: ShareASmile