add requires for dash, s
Merge pull request #64 from egh/master

add requires for dash, s
Use markdown-toc to generate TOC, and fix heading typo.
Bind kill-buffer to the k key.
Merge pull request #65 from holocronweaver/master

Bind kill-buffer to the k key.
Mention new kill-buffer keybinding in the README.
Merge pull request #66 from holocronweaver/master

Mention new kill-buffer keybinding in the README.