Add package level README.md for core-httpclient-impl#303

Merged

mikecdavis merged 7 commits intomasterfrom

mikecdavis/OASIS-4503-add-readme

May 22, 2019

Commits on May 20, 2019

First attempt at documentation.
Mike Davis
committed
Minor style tweaks.
Mike Davis
committed
Fix markdown.
Mike Davis
committed
Fix syntax errors.
Mike Davis
committed
Add coverage.
Mike Davis
committed

Commits on May 22, 2019

Add links.
Mike Davis
committed
Trigger build.
Mike Davis
committed