Readme improvement

[KjellKod]

PULL REQUEST DESCRIPTION

ADD CONTENT HERE TO DESCRIBE THE PURPOSE OF THE PULL REQUEST

Testing Advice

step 1

mkdir build; cd build; cmake -DADD_G3LOG_UNIT_TEST=ON ..

// linux/osx alternative, simply run: ./scripts/buildAndRunTests.sh

step 2: use one of these alternatives to run tests:

• Cross-Platform: ctest
• or ctest -V for verbose output
• Linux: make test

CHECKLIST TO COMPLETE

• TDD: New/modified code must be backed down with unit test - preferably Test Driven Development style development)
• Documentation: All new/modified functionality should be backed up with API documentation (API.markdown or README.markdown)

Cross-Platform Testing

• CI GitActions: (Linux, OSX) + AppVeyor-CI (Windows)\
• Local/VM testing, at least one of the following: Windows, Linux, OSX