Editorial - Add Governance Section to all the namespaces

[bumblefudge]

In the process of transforming 12 CAIPs into 11 Namespaces, I gradually realized that since many developers will be encountering new ecosystems for the first time, a link to the EIP/BIP-equivalent protocol-upgrade governance process/archive may be as important as links to the Developer Docs for SDKs and node APIs. I already included links to these in most of the ## References sections, but someone (maybe me, if no one else does it) should go through and add a "## Governance" section to all the README.mds. I added this to the template at the very last minute, the only README that already has one is the Hedera one.