docs: fix numaperf.rst and add it to the doc tree

Commit 13bac55ef7ae ("doc/mm: New documentation for memory performance")
added numaperf.rst, but did not add it to the TOC tree.  There was also an
incorrectly marked literal block leading to this warning sequence:

  numaperf.rst:24: WARNING: Unexpected indentation.
  numaperf.rst:24: WARNING: Inline substitution_reference start-string without end-string.
  numaperf.rst:25: WARNING: Block quote ends without a blank line; unexpected unindent.

Fix the block and add the file to the document tree.

Fixes: 13bac55ef7ae ("doc/mm: New documentation for memory performance")
Cc: Keith Busch <[email protected]>
Reviewed-by: Mike Rapoport <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>

0 files changed, 0 insertions, 0 deletions