Add OSSF Scorecard GH Action and badge to README

[kjaymiller]

Using this action help us keep track of our OSSF Health and Safety Score of this project.

• https://github.com/ossf/scorecard-action

WHY

to help open source maintainers improve their security best practices and to help open source consumers judge whether their dependencies are safe.

[CyrilBaah]

Hi @kjaymiller, would like to work this issue.