Add cert usage information, update READMEs

[derisen]

Pull Request

Purpose

• Adds cert usage information
• Update READMEs with links to cert docs

Does this introduce a breaking change

    [ ] Yes
    [ x ] No

Pull request type

What kind of change does this Pull Request introduce?

    [ ] Bugfix
    [ x ] Feature
    [ ] Code style update (formatting, local variables)
    [ x ] Documentation content changes
    [ ] Other... Please describe:

How to test

• Get the code

    git clone [repo-address]
    cd [repo-name]
    git checkout [branch-name]
    npm install

What to check

ex: verify that the following are valid:

• ...

Other Information