Add Flitdrop to File Sharing

[MrFrosas]

Adds Flitdrop under File Sharing (alphabetical, between Dropshare and Flow).

• What it is: a free tool to send files, photos and clipboard between any phone and any computer over the local Wi-Fi. Nothing to install on the phone — you just scan a QR code once. Transfers are end-to-end encrypted.
• Homepage: https://flitdrop.com/
• License: free (freeware icon used, not the OSS icon).
• Works alongside the already-listed LocalSend / NearDrop, cross-platform including macOS.

Single addition, alphabetically placed, icon reference reused from the existing list. Thanks for maintaining this list!