Update repositories.txt

[crane-elec]

Added EthernetSP Library.

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/crane-elec/EthernetSP:

Linting library in EthernetSP
WARNING: Empty library.properties includes field. Please either define includes or remove this optional field. 
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format
         (Rule LP051)                                                                                          
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, 2 WARNINGS

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Linting sketch in EthernetSP/examples/LinkStatus

Linter results for project: no errors or warnings

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Linting sketch in EthernetSP/examples/TelnetClient

Linter results for project: no errors or warnings

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Linting sketch in EthernetSP/examples/WebServer

Linter results for project: no errors or warnings

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

Linter results for projects: 0 ERRORS, 2 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/crane-elec/EthernetSP/