Adding Pairdrop to File Transfer - Single-click & Drag-n-drop Upload (#3821)

- remove SnapDrop (superseded by PairDrop)
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/pull/3821

Co-authored-by: nodiscc <nodiscc@gmail.com>

README.md

@@ -970,6 +970,7 @@ Simplified file servers for sharing of one-time/short-lived/temporary files, pro
 - [Kleeja](https://kleeja.net/) - File Upload/sharing application, used by thousands of webmasters since 2007. ([Source Code](https://github.com/kleeja-official/kleeja)) `GPL-2.0` `PHP`
 - [lufi](https://framagit.org/fiat-tux/hat-softwares/lufi) - Let's Upload that FIle, client-side encrypted. ([Demo](https://demo.lufi.io), [Source Code](https://framagit.org/fiat-tux/hat-softwares/lufi/tree/master)) `AGPL-3.0` `Perl`
 - [OnionShare](https://github.com/onionshare/onionshare) - Securely and anonymously share a file of any size. `GPL-2.0` `Python`
+- [Pairdrop](https://github.com/schlagmichdoch/pairdrop) - Local file sharing in your browser. Inspired by Apple's AirDrop. Fork of Snapdrop. `GPL-3.0` `Docker`
 - [PicoShare](https://pico.rocks) - A minimalist, easy-to-host service for sharing images and other files. ([Demo](https://demo.pico.rocks), [Source Code](https://github.com/mtlynch/picoshare)) `AGPL-3.0` `Go`
 - [Picsur](https://github.com/rubikscraft/Picsur) - A simple imaging hosting playtfom that allows you to easily host, edit, and share images. `GPL-3.0` `Docker`
 - [PictShare](https://www.pictshare.net/) - PictShare is a multi lingual, open source image hosting service with a simple resizing and upload API. ([Source Code](https://github.com/HaschekSolutions/pictshare)) `Apache-2.0` `PHP`
@@ -982,7 +983,6 @@ Simplified file servers for sharing of one-time/short-lived/temporary files, pro
 - [Share](https://github.com/MrDemonWolf/share) - Simple yet advanced uploader - upload files, images and text with moderation tools for admins. Can be used for friends and family or just for you. Integration with ShareX and more. `MIT` `Nodejs`
 - [Sharry](https://github.com/eikek/sharry) - Share files easily over the internet between authenticated and anonymous users (both ways) with resumable up- and downloads. `GPL-3.0` `Scala/Java`
 - [Shifter](https://github.com/TobySuch/Shifter) - A simple, self-hosted file-sharing web app, powered by Django. `MIT` `Docker`
-- [Snapdrop](https://snapdrop.net/) - Local file sharing in your browser. Inspired by Apple's Airdrop. ([Source Code](https://github.com/RobinLinus/snapdrop)) `GPL-3.0-only` `Docker`
 - [transfer.sh](https://transfer.sh) - Easy file sharing from the command line. ([Source Code](https://github.com/dutchcoders/transfer.sh)) `MIT` `Go`
 - [Uguu](https://uguu.se/) - Stores files and deletes after X amount of time. ([Source Code](https://github.com/nokonoko/uguu)) `MIT` `PHP`
 - [Uploady](https://github.com/farisc0de/Uploady) - Uploady is a simple file uploader script with multi file upload support. `MIT` `PHP`