Create activity.md
Remove activity summary page, because use index instead
Add some files to ignores
Add redcarpet options
Use `left` theme

[left](https://github.com/holman/left) is an open-source theme of
Jekyll created by [Zach holman](https://github.com/holman).

It's simple and easily available to customize.
Add members and rules
Merge branch 'master' into add-activities

Conflicts:
	_config.yml
	_layouts/default.html
	_layouts/top.html
	members.md
	rules.md
Fix url
Merge pull request #3 from JavaKueche/new-theme