Update README.md

wiki in readme

README.md

@@ -12,12 +12,15 @@ as well as its exercise and solution manual. When downloading or cloning this re
 2. All Fortran codes for the solution manual are stored in the folder [code-solution](https://github.com/fabiankindermann/ce-fortran/tree/main/code-solution).
 3. Installation instructions and packages for different operating systems as well as Docker containers can be found in the folder [installation](https://github.com/fabiankindermann/ce-fortran/tree/main/installation). Just choose your operating system and learn how to install a Fortran compiler and our toolbox on your computer. Refer to the `README.md` files for further instructions.
 
+## Wiki
+
+In our [wiki](https://github.com/fabiankindermann/ce-fortran/wiki), you can find a full documentation of the ce-fortran toolbox.
+
 ## Further Information
 
 For further information, please visit www.ce-fortran.com.
 
 There you will find:
-1. A documentation of the toolbox.
-2. A forum for discussion about certain issues.
-3. A collection of links for further developing your programming skills.
+1. A forum for discussion about certain issues.
+2. A collection of links for further developing your programming skills.