doc: rename docs to doc to match xenopsd

Signed-off-by: David Scott <dave.scott@citrix.com>
doc: rename evolution/ to futures/ to match xenopsd

Signed-off-by: David Scott <dave.scott@citrix.com>
doc: add basic skeleton matching Xenopsd

Signed-off-by: David Scott <dave.scott@citrix.com>
docs: convert the XenAPI evolution design to markdown

Signed-off-by: David Scott <dave.scott@citrix.com>
docs: correct the link to the evolution document

Signed-off-by: David Scott <dave.scott@citrix.com>
docs: XenAPI evolution: remove ``latex''-ism

Signed-off-by: David Scott <dave.scott@citrix.com>
doc: describe some of the memory accounting

Signed-off-by: David Scott <dave.scott@citrix.com>
doc: link the memory accounting into the index

Signed-off-by: David Scott <dave.scott@citrix.com>
doc: add a missing bracket to the shadow formula

Signed-off-by: David Scott <dave.scott@citrix.com>
Merge pull request #2002 from djs55/lots-of-docs

docs: add a basic doc skeleton