Documentation: Add notes for first time setup of the project in CLion

Mention the "Open Project Wizard" where you can set
the CMake options before making the cache.
Remind users to use the "Default" build type
and to build the Toolchain so CMake does not complain.

Documentation/CLionConfiguration.md

@@ -2,13 +2,24 @@
 
 CLion can integrate with CMake to provide code comprehension features.
 
-After opening the `serenity` repository in CLion as a new project, go to "`File->Settings->Build, Execution, Deployment->Cmake`",
-and set the following fields: (Assuming you use `Ninja` as the build system and configured the CMake build directory to `Build/i686`)
+After opening the `serenity` repository in CLion as a new project, the "`Open Project Wizard`" window will open, from here set the following fields:
+
+(Assuming you use `Ninja` as the build system and configured the CMake build directory to `Build/i686`)
+
+`Build type`: `Default`
+
+> _CMake will complain with any other build type, make sure to use `Default` so that `CMAKE_BUILD_TYPE` is empty in the `Build/i686/CMakeCache.txt` file._
 
 `CMake Options`: `-G Ninja -DBUILD_LAGOM=ON -DCMAKE_C_COMPILER=gcc-10 -DCMAKE_CXX_COMPILER=g++-10`
 
 `Build Directory`: `Build/i686`
 
+> _If you have not built the Toolchain at this point, please do so: `./Toolchain/BuildIt.sh`_
+
+If you already have the project open, you can go to "`File->Settings->Build, Execution, Deployment->Cmake`" to find these options.
+
+Remember to recreate the CMake cache after changing any of the options.
+
 ## Excluding Build Artifacts
 
 Source files are copied to the `Build` directory during the build, if you do not exclude them from CLion indexing they will show up