tixing fypos

README.md

@@ -44,7 +44,7 @@ Simply run `make doc` to generate all documentation (*after* the CMake step).  D
 + [`devel/git`](https://www.freshports.org/devel/git/) **or** [`devel/git-gui`](https://www.freshports.org/devel/git-gui/) (these ports are mutually exclusive, you can only have one of them installed)
 + [`devel/cmake`](https://www.freshports.org/devel/cmake/)
 + CLang from the base system (`4.0.0`) is all that's required to build.  No need for extra compilers from Ports or `pkg`.
-+ ['devel/doxygen`](https://www.freshports.org/devel/doxygen/)
++ [`devel/doxygen`](https://www.freshports.org/devel/doxygen/) Needed to build developer documentation, which is optional.
 
 ---
 ## Building the NDE