Add git dir to script installation instructions

[childish-sambino]

Proposed changes

Fixes script install path.

Type of change

What type of change does your code introduce to the provider? Please put an x (w/o heading/trailing white spaces)
in the boxes that apply:

• Bug-fix (change that fixes current functionality)
• New feature (change that adds new functionality)

Checklist

Please put an x (w/o heading/trailing white spaces) in the boxes that apply:

• I have read and followed the CONTRIBUTING guidelines
• I have made sure code compiles correctly
• I have run 'make test' locally from the terraform_provider_api folder and no errors were found
• I have added tests that prove my fix is effective or that my feature works
• I have added/updated necessary documentation (if appropriate)

[dikhan]

Thanks for contributing @childish-sambino, good catch.