Update repositories.txt

[SergeSkor]

No description provided.

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/SergeSkor/SSVXYMatrix:

Linting library in SSVXYMatrix
Rule LD001 result: fail
WARNING: No readme found. Please document your library. See: https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/about-readmes
Rule LD002 result: fail
WARNING: No license file found. See: https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/licensing-a-repository#detecting-a-license

Finished linting project. Results:
Warning count: 2
Error count: 0
Rules passed: true

-------------------

Linting sketch in SSVXYMatrix/examples/FastLED_XYMatrix_example1

Finished linting project. Results:
Warning count: 0
Error count: 0
Rules passed: true

-------------------

Finished linting projects. Results:
Warning count: 2
Error count: 0
Rules passed: true

[github-actions]

Your submission has now been accepted! Thanks for your contribution to the Arduino Library Manager index.

The library(s) will be available for installation via Library Manager within a day's time.

You can check the logs from the Library Manager indexer for your library(s) here:
http://downloads.arduino.cc/libraries/logs/github.com/SergeSkor/SSVXYMatrix/