Readme

See #42, release log:

• 58fcea0 by @kniazkov: Merge pull request #42 from kn...
• 5674d64 by @kniazkov: NullNode
• f40b417 by @kniazkov: README
• c6e83d2 by @kniazkov: README
• a8a4518 by @kniazkov: README
• 718ea94 by @kniazkov: README
• fac4bee by @kniazkov: README
• a95d421 by @kniazkov: README

Released by Rultor 2.0-SNAPSHOT, see build log