[UI/UX] Reorganize README (T15105)
Changelog
- Removed TODOs & Plans from README since we are using Phabricator now
- Updated Lucas' website URL to the correct working one
- Lowered minimum iOS version to participate in TestFlight from 15 to 14
- Restructured README to have a clearer division between sections
- Misc wording and style changes
Preview
https://invent.kde.org/apollozhu/kdeconnect-ios/-/tree/update-readme
Edited by Apollo Zhu