chore: remove march-madness from bundled plugin-repos

March Madness is now available in the ledmatrix-plugins monorepo store
(ChuckBuilds/ledmatrix-plugins/plugins/march-madness) and should be
installed via the Plugin Store like any other plugin.

Removing the bundled copy so new installs don't automatically include it.
Existing users keep their installed version until they choose to uninstall.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -1,10 +1,5 @@
 # LEDMatrix
-[![License](https://img.shields.io/badge/license-GPL--3.0-green)](LICENSE)
-[![Discord](https://img.shields.io/badge/Discord-community-5865F2?logo=discord&logoColor=white)](https://discord.gg/RdrC37rEag)
-[![GitHub Stars](https://img.shields.io/github/stars/ChuckBuilds/ledmatrix?style=flat&color=yellow)](https://github.com/ChuckBuilds/ledmatrix)
 [![Codacy Badge](https://app.codacy.com/project/badge/Grade/77fc9b446a5948e5b0aed7a7aaeb1bab)](https://app.codacy.com/gh/ChuckBuilds/LEDMatrix/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
-
-
 ## Welcome to LEDMatrix! 
 Welcome to the LEDMatrix Project! This open-source project enables you to run an information-rich display on a Raspberry Pi connected to an LED RGB Matrix panel. Whether you want to see your calendar, weather forecasts, sports scores, stock prices, or any other information at a glance, LEDMatrix brings it all together.