mm,doc: Add new documentation structure

mm,doc: Add new documentation structure

Closely following the outline of Mel Gorman's book "Understanding the
Linux Virtual Memory Manager", add a new outline.  Preserve the current
contents of the mm underneath the new outline so we can transition those
documents to a more sensible place later.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Corbet <[email protected]>