Corrected five comma errors in `topic_01`'s `README.md`

The comma errors I corrected are:

"Unix shell, called the "Thompson Shell" (sh for short), in 1971" (commas added)
"the most famous is Stephen Bourne, who wrote the Bourne shell in 1979" (comma added)
"Almquist shell (ash), which was written by Kenneth Almquist in 1980; BSD-licensed" (comma added)
"The Bourne-Again shell (bash), which was written by Brian Fox in 1989; GPL-licensed" (comma added)
"The Debian-Almquist shell (dash), written by Herbert Xu ini 1997; GPL-licensed" (comma added)

This is for .5 points of EC, I believe; if I have to pull request them separately to get 0.1 each, I would be happy to do so.

mikeizbicki / cmc-csci143