The 16MB hash table extent size did not serve any useful defragmentation
or compression purpose, and for very small filesystems (under 100GB),
16MB is much larger than necessary.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
Split the rather large README into smaller sections with a pitch and
a ToC at the top.
Move the sections into docs/ so that Github Pages can read them.
'make doc' produces a local HTML tree.
Update the kernel bugs and gotchas list.
Add some information that has been accumulating in Github comments.
Remove information about bugs in kernels earlier than 4.14.
Signed-off-by: Zygo Blaxell <bees@furryterror.org>
