idr: Add documentation

Move the idr kernel-doc to its own idr.rst file and add a few
paragraphs about how to use it.  Also add some more kernel-doc.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
This commit is contained in:
Matthew Wilcox 2018-02-06 15:05:49 -05:00
commit ac665d9423
4 changed files with 95 additions and 13 deletions