Updated link to indent specification in readme

[KevinGreene]

Before submitting a PR make sure the following things have been done (and denote this
by checking the relevant checkboxes):

• The commits are consistent with our contribution guidelines
• You've added tests (if possible) to cover your change(s). Indentation & font-lock tests are extremely important!
• All tests are passing (make test)
• The new code is not generating bytecode or M-x checkdoc warnings
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the readme (if adding/changing user-visible functionality)

Thanks!

[bbatsov]

Can you please change Updated to Update in your commit message?

[Malabarba]

That URL 404s for me.

[Malabarba]

Besides, we should probably point to the new manual. :-)

[bbatsov]

The link works for me, but yeah - probably it'd best to link to cider.readthedocs.org.

[KevinGreene]

I've fixed the commit message (removed d) and now point to http://cider.readthedocs.org/en/latest/indent_spec/

[bbatsov]

👍 Thanks!