should we have a new 'tools' manual?

[Peter Maydell]

So far we've been converting docs to Sphinx and assigning them
to manuals according to the division originally set out by
Paolo on the wiki: https://wiki.qemu.org/Features/Documentation

 * QEMU User-mode Emulation User's Guide (docs/user)
 * QEMU System Emulation User's Guide (docs/system)
 * QEMU System Emulation Management and Interoperability Guide (docs/interop)
 * QEMU System Emulation Guest Hardware Specifications (docs/specs)
 * QEMU Developer's Guide (docs/devel, not shipped to end-users)

but some of our documentation has always been a bit of an awkward
fit into this classification:
 * qemu-img
 * qemu-nbd
 * virtfs-proxy-helper
etc. I've tended to put these things into interop/.

The proposal from Dan and David was that we should add a sixth
top-level manual
 * QEMU Tools Guide (docs/tools)

which would be a more coherent place for these to live.

This seems like a good idea to me -- do people agree? What's
our definition of a "tool", or do we just know one when we see it?
What in particular should go in tools/ ?

thanks
-- PMM