DOC: provide more inline examples for cookbook.rst

[jreback]

In-line examples when not too long are nice (as well as the link)

for example: 6fe9539

[jnmclarty]

I'm working on this. Feedback on style (too brief vs too verbose) is welcome, as I do this. I'll push to my repo, after any commits I do.

[jnmclarty]

Sneak peek is here: https://github.com/jnmclarty/pandas/blob/cookbook_inline_examples/doc/source/cookbook.rst

[jnmclarty]

Best to view the diff in split mode, cause I'm tweaking some of the titles of each section. Mainly to remove 'How to ...'; the entire thing is a how to. Hopefully this link captures what I want it to:
jnmclarty@89d982e#diff-35c6bdcde00a9f03ee755d33ee1e22e9