add a few simple examples

See #157, release log:

• 39b20e1 by @yegor256: #157: clean
• cc1506b by @yegor256: #157: wraps fixed
• 23cad13 by @yegor256: #157: fixes
• 6917fcc by @yegor256: #157 new examples
• 0640d04 by @yegor256: #155 badge

Released by Rultor 1.69.1, see build log