Update download from Github instructions in README.md

Updated and improved the instructions for downloading from GitHub for clarity.

name: Update README.md about: GenderMag Recorders Assistant project

What does this implementation fix? Explain your changes.
Removes unnecessary cloning step for installing from GitHub and updates and clarifies others.
Does this close any open issue? (Give issue id from issue tracker) N/A
Include any related logs, error, output file etc. N/A
Did you test on Mac and Windows? N/A
Did you test the full GM process and verify that the code does not contribute any unexpected errors/bugs? N/A
Did you follow the style guidlines and verify that the code does not have any incorrect formatting? N/A
If possible, provide a screenshot of the functionality. N/A
Any other information?

GenderMagProject / GenderMagRecordersAssistant