Moved to InnerSource as a term, changed formatting, shortened name

[MaineC]

I believe this pattern does need a bit of love. I only made some first changes to the name "InnerSource", changed some formatting and shortened the name.

However I believe the solutions given are incomplete in particular wrt. build chain solutions to the issue. It might make sense to mention explicit release naming and numbering schemes. It might make sense to mention the option of setting up build systems to trigger new builds on upstream code changes or upstream releases.