Clean up docs in repository
Solves #167
- README.md (Development section)
- README.md (the rest)
- doc/README.md (Governance setion)
- doc/README.md (the rest)
- doc/build-unix.md
- doc/coding-style.md
- doc/governance.md
- doc/release-notes.md
- doc/unit-tests.md
- doc/masternode-config.md
- doc/masternode-guide-startmany.md