Add Telegram group link to README

[Andyporras]

Description

This PR adds a Community & Support section to the README with a link to the OSMTracker Telegram group.
It provides a space for users, contributors, translators, and developers to join the community for real-time discussions and support.
GitHub Issues will remain the primary channel for bug reports and feature requests.

Related issues

Related to the pr:

• Telegram group #602

Pull Request Checklist

• The PR is proposed to the proper branch.
• The changes have been tested on the target Android API and minimum Android API (not applicable).
• Automated tests have been added (not applicable).
• The feature is well documented (not applicable)..
• There is a reference to the original bug report or related work (not aplicable).