Rebrand as Twitcher for Redot

[dominicbytes]

What changed

• presents the project and addon as Twitcher for Redot
• replaces Godot-facing installation and runtime labels with Redot equivalents
• adds Redot-specific repository documentation and discovery metadata
• directs the bundled example back to this Redot repository

Relationship to the original

This is an independent Redot project derived from kani_dev's original Twitcher: https://github.com/kanimaru/twitcher

The README prominently preserves that attribution and explains that this project is maintained separately and will not merge back into the original.

Validation

• isolated compatibility probe passed on Redot 26.2 stable (4f5b14aba)
• secret scan passed
• pinned Redot 26.2 GitHub Actions run passed