add content to Code coverage section

[jeffpaul]

Is your enhancement related to a problem? Please describe.
Our Code coverage section of the GitHub Process page needs some details added about how to add code coverage to a repo (with an officially recommended tool) and how to add its related badge to the readme.md file.

Describe the solution you'd like

• add recommended code coverage tool, how to setup on repo
• add coverage badge details
• capitalize coverage in section title
• remove hidden <!-- @todo: add coverage badge details -->

Designs
n/a

Describe alternatives you've considered
n/a

Additional context
n/a