Tweak documentation thoroughly; still incomplete.

Tweak documentation thoroughly; still incomplete.

* README: Minor tweaks.

* muse.texi: Massively rename chapters so that the titles are more
  descriptive.  Clean up grammar.

* muse.texi (Obtaining Muse): Move content of Installation node here,
  stripping out any customization tips, since those are covered later.
  Re-work this chapter since I was dissatisfied with it.

* muse.texi (Installation): This node has the content of README regarding
  installation, which fits the title of the node much better than the
  previous content.

* muse.texi (Blosxom): Turn the sections of this section into
  subsections.

* muse.texi (Getting Help and Reporting Bugs): Turn this into a list.  I
  like lists!

* muse.texi (History): Add a "2005" item.
git-archimport-id: mwolson@gnu.org--2005/muse--main--1.0--patch-69