Update README.md

Update README.md

Merge pull request #105 from senorcris/feature/github

github sample configuration

adding authentication for using github keys

adding passport-github support

Merge pull request #102 from scollett/gitignore_custom_themes

Merge pull request #101 from egh/feature/emoticons-require-breaks

Do not track custom css/img/js

Ignore local custom themes. Only track the default theme.

Merge pull request #100 from scollett/fix_defaults_override_custom

do not replace emoticons in longer strings

Stop defaults in env.js overriding config.json values

Merge pull request #99 from scollett/set_session_age

Fix missing comma for json sample config.