Update repositories.txt

[acornelissen]

Added https://github.com/acornelissen/DTS6012M_UART to the repository list.

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/acornelissen/DTS6012M_UART:

Linting library in DTS6012M_UART
WARNING: No license file found.                                                                                                                 
         See:                                                                                                                                   
         https://docs.github.com/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/licensing-a-repository
         (Rule LD002)                                                                                                                           

Linter results for project: 0 ERRORS, 1 WARNINGS

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Linting sketch in DTS6012M_UART/examples/DTS6012M_UART_Example

Linter results for project: no errors or warnings

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

Linter results for projects: 0 ERRORS, 1 WARNINGS

[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/acornelissen/DTS6012M_UART/