"++" string interpreted as underline in Markdown README.md, breaks C++ code (BB-9634)

Text included between two occurrences of the "++" string in the same paragraph is rendered as underlined in the HTML representation of a Markdown README.md file.

This is unfortunate when you have to write things like "C++" all over the place.

I believe the "++" modifier is not part of the Markdown syntax.

Note that I had to break up this message into four paragraphs to get the "++" string to display properly.