toplevel doc, first draft

[Michael Elizabeth Chastain]

There is a list of standard targets in "info make", node
"standard targets for users".

I think it would be fine to say: "the standard targets (all, install,
info, et cetera)" as documented in 'info make', node 'standard targets
for users'".  People are very inductive and love examples, and then
you can point to an authoritative list.

I read all the notes.  They struck me as great notes that need preservation,
but they could use more narrative to tie them all together.  But as long
as they are accurate then any docs are fine with me.  My two cents.

Michael C