cleanup of README

README.md

@@ -31,7 +31,7 @@ Getting started
 In order to build a MultiMesh, simply wrap your host-grid type into a the
 `MultiMesh` class and set the number of grids to construct.
 
-```
+```c++
 using HostGrid = ALUGrid<2, 2, simplex, conforming>;
 MultiMesh<HostGrid> multimesh(2);
 ```
@@ -39,7 +39,7 @@ MultiMesh<HostGrid> multimesh(2);
 If the host-grid allows to pass arguments to its constructo, these can be
 appended to the MultiMesh constructor after the size argument, e.g.
 
-```
+```c++
 using HostGrid = AlbertaGrid<3,3>;
 MultiMesh<HostGrid> multimesh(2, filename);
 ```
@@ -53,7 +53,7 @@ constructor creates one grid only. (This is just to be conform the the
 GridFactory interface). In order to use, e.g. structured grid-factory builders,
 you have to pass the MultiMesh GridFactory:
 
-```
+```c++
 using HostGrid = ALUGrid<2, 2, simplex, conforming>;
 using Factory = StructuredGridBuilder<MultiMesh<HostGrid> >;
 GridFactory<MultiMesh<HostGrid> > gridFactory(3); // create 3 grids