I've reviewed the docs for English and general readability. As
mentioned, I've no idea of the tech involved. I did look through the
bdb.py source and the existing docs for pdb to get some idea of the
terminology used. Ultimately I've changed very little; in a couple of
places the English was just wrong and in a couple of others I felt a
small change improved things.

One thing I couldn't work out is that arklad, the author, used "canonic"
throughout which I've never seen used. I would simply have changed it to
"canonical" except that the code itself uses "canonic" as a function
name! In addition, there's no explanation of what canonic(al) means in
the context. I've left ?TJG? marks around all the instances.