[Mono-docs-list] missing period in "C# compiler Command-line options"

[Manuel Lora]

Missing period in "C# compiler Command-line options" at the end of:

--about
Displays information about the Mono C# compiler

(the rest of the compiler switches examples have them, so this makes
them all match).

Same issue on the manpage, since I assume it's taken straight from it.

ml