Add Artron_DS1338 lib

[maxpromer]

DS1338 is RTC ic, use it library with Arduino IDE and any Arduino board

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/ArtronShop/Artron_DS1338:

Linting library in Artron_DS1338
WARNING: library.properties name Artron DS1338 contains spaces. Although supported, best practices is to not use spaces.
         (Rule LP015)                                                                                                   
WARNING: The library.properties paragraph field repeats the sentence field. These are displayed together so redundancy  
         is not needed. (Rule LP036)                                                                                    
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
         (Rule LD002)                                                                                                                                 

Linter results for project: 0 ERRORS, 3 WARNINGS

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Linting sketch in Artron_DS1338/examples/DS1338_set_get_datetime

Linter results for project: no errors or warnings

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Linter results for projects: 0 ERRORS, 3 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/ArtronShop/Artron_DS1338/