fix the automatic compile MEX section

Author: korbinian90

docs/development/compilation/index.md

@@ -24,13 +24,16 @@ Platform-specific throubleshooting is available with the links above. We list he
 
 !!! info "How is the recompilation triggered?"
 
-    If new c files or changes are pushed to main, the [compile MEX](https://github.com/spm/spm/actions/workflows/compile_mex.yml) action will automatically run and recompile all MEX files. In can also be triggered manually, which works for a any branch.
+    If new `.c, .cpp, .h or .hpp` files or changes of those are pushed to `main`, the [compile MEX](https://github.com/spm/spm/actions/workflows/compile_mex.yml) action will automatically run and recompile all MEX files. In can also be triggered manually, which works for a any branch.
 
-The compiled MEX files will be available as zip a file under the [compile MEX](https://github.com/spm/spm/actions/workflows/compile_mex.yml) action by selecting the corresponding run of the action and downloading the spm-mex-all.zip file. It contains compiled MEX files for Windows, Linux, MacOS (Intel) and MacOS (Apple Silicon).
+The compiled MEX files will be available as zip a file under the [compile MEX](https://github.com/spm/spm/actions/workflows/compile_mex.yml) action by selecting the corresponding run of the action and downloading the `spm-mex-all.zip` file. It contains compiled MEX files for Windows, Linux, MacOS (Intel) and MacOS (Apple Silicon).
 
 The suggested steps after changing or adding new c code is:
-1. Confirm that the [automatic tests](https://github.com/spm/spm/actions/workflows/matlab.yml) still succeed
-2. Download the [automatically compiled MEX files](https://github.com/spm/spm/actions/workflows/compile_mex.yml)
-3. Manually add the MEX files of the corresponding change to the SPM repository (.mexa64, .mexmaca64, .mexmaci64, .mexw64)
+
+    1. Confirm that the [automatic tests](https://github.com/spm/spm/actions/workflows/matlab.yml) still succeed
+
+    2. Download the [automatically compiled MEX files](https://github.com/spm/spm/actions/workflows/compile_mex.yml)
+
+    3. Manually add the MEX files of the corresponding change to the SPM repository (.mexa64, .mexmaca64, .mexmaci64, .mexw64)
 
 Note: Currently, the action doesn't compile the external c dependencies. This is because of a problem of compiling the fieldtrip dependency on windows.