Restructure as a stand-along project

The previous two commits were cherry-picked out of
git://tremily.us/blog.git (where they were commits 1f0bb05 and
b85f840).

diff --git a/posts/Maple.mdwn b/README.md
similarity index 100%
rename from posts/Maple.mdwn
rename to README.md

diff --git a/posts/Maple/example.mw b/example.mw
similarity index 100%
rename from posts/Maple/example.mw
rename to example.mw

diff --git a/posts/Maple/mw2txt.py b/mw2txt.py
similarity index 100%
rename from posts/Maple/mw2txt.py
rename to mw2txt.py