Update README.md

README.md

@@ -30,6 +30,7 @@ for details about the installation of dune modules.
 Additionally we require the following libraries to be found:
 - [MTL4](https://gitlab.math.tu-dresden.de/spraetor/mtl4) (use this fork to get up-to-date changes)
 - [SuiteSparse](http://faculty.cse.tamu.edu/davis/suitesparse.html) (optional)
+- libalberta >= 3.0 (For Alberta-Grids)
 
 And a compiler that supports the C++14 standard, e.g. g++ >= 4.9 and clang >= 3.6, and cmake >= 3.1.