- toplevel README received some long-needed refactoring
  + lowlevel detail moved, well, to lowlevel READMEs
- reflected more thoroughly that m-p is not about distros anymore
- dropped features.in/00example/README.en: it's already out-of-date
  a bit, and there's no perceived need in thorough English docs so far
- wiki article got split into parts and somewhat rewritten, links updated
- mv doc/{CodingStyle,style.txt}

This was tackled before but it took raorn@'s hint regarding
sys-freedos-linux (ms-sys has no bootsectors compatible with
freedos currently) and gns@' quick rush at make-freedos-floppy
script to wrap things up.

Should be further developed to become actually useful though.