README: misleading lock-in statement

The documentation is wildly misleading. Everything in this project gets locked behind a for-profit, closed source, proprietary service in Microsoft GitHub. It’s misleading to say that this isn’t tracked and has no lock-in, when it clearly does. We would be better off leveraging the *decentralized* part of decentralized version control systems (DVCS) instead of centralizing around a service like Microsoft GitHub. Feel free to close and fix the wording yourself. The rewording is facetious on purpose, but there is truth to the sentiment. (Merge requests always get more attention, and I’d email you a patch, but we’re locked into this platform’s source control model)