Add ATtiny_TimerInterrupt Library

[khoih-prog]

Initial Release v1.0.0

1. Intial release to support Arduino AVR ATtiny-based boards (ATtiny3217, etc.) using megaTinyCore
2. Add notes howto upload by drag-and-drop to CURIOSITY virtual drive

[github-actions]

Arduino Lint has suggestions for possible improvements to https://github.com/khoih-prog/ATtiny_TimerInterrupt:

Linting library in ATtiny_TimerInterrupt
WARNING: library.properties name value ATtiny_TimerInterrupt is longer than the recommended length of 16 characters.
         See: https://arduino.github.io/arduino-cli/latest/library-specification/#libraryproperties-file-format     
         (Rule LP010)                                                                                               

Linter results for project: 0 ERRORS, 1 WARNINGS

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Linting sketch in ATtiny_TimerInterrupt/examples/Argument_Complex

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/Argument_None

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/Argument_Simple

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/Change_Interval

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/Change_Interval_HF

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/FakeAnalogWrite

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/ISR_16_Timers_Array_Complex

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/ISR_RPM_Measure

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/ISR_Timers_Array_Simple

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/RPM_Measure

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/SwitchDebounce

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/TimerDuration

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/TimerInterruptTest

Linter results for project: no errors or warnings

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Linting sketch in ATtiny_TimerInterrupt/examples/multiFileProject

Linter results for project: no errors or warnings

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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/khoih-prog/ATtiny_TimerInterrupt/