Add fastlane structure

[goyalyashpal]

Please verify urself too - i have tried my best to avoid errors, but please check properly.

Have added the fastlane structure which can be used to automate the publishing of apps to stores (aimed at fdroid in this MR).

• thing: source
• fastlane structure: snippet
• full_description: from Google Play Store's listing + small modification for including one more keyterm
• short_description: from intro in Readme + correction from Repo's About/Description + Succint-ified
• phoneScreenshots: from GPStore
• changelogs: from GPStore

[goyalyashpal]

link rain for articles referred

Some examples i looked at (in f-droid website): - short_description : (lack of full stop) and changelog : (heading + list) from [Easer](https://f-droid.org/en/packages/ryey.easer.beta/) - [src](https://github.com/renyuneyun/Easer/blob/master/fastlane/metadata/android/en-US/changelogs/124999.txt) - Chengelog list without bullets: [NewPipe](https://f-droid.org/packages/org.schabi.newpipe) - [src](https://github.com/TeamNewPipe/NewPipe/blob/dev/fastlane/metadata/android/en-US/changelogs/968.txt) - List in full_description: [Tuner](https://f-droid.org/en/packages/de.moekadu.tuner) - [src](https://github.com/thetwom/Tuner/blob/master/fastlane/metadata/android/en-US/changelogs/6.txt) Link to helping sources: - [snippet](https://gitlab.com/snippets/1895688) shared by @ izzysoft [..](https://gitlab.com/fdroid/rfp/-/issues/1728#note_570536689) - confirmation for using [fastlane to deploy to gpstore](https://duckduckgo.com/?q=fastlane+to+deploy+to+google+play&t=vivaldi&ia=web) - this stmt was mentioned in the snippet itself. - app using FL for gp too: [Quote Unquote](https://f-droid.org/packages/com.github.jameshnsears.quoteunquote) - [src](https://github.com/jameshnsears/QuoteUnquote) - definitely seems worth studying