tree 883450327e44a026bda203bde27be1a4c42fb152
parent eea7decfa48ce3b49e219d61829aac8c058641f6
author Ed Tanous <edtanous@google.com> 1611774938 +0000
committer Ed Tanous <edtanous@google.com> 1611775360 -0800

Update subtree documentation

subtrees are no longer used, but leave a tombstone statement here for a
while just in case someone gets confused about why the meta-* layers are
there.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Idc9f05870d331f4466dc640d13dc99a87b948165