WSL2 is now available in non-insider builds of Windows, starting
with version 2004.
Add a filesystem note regarding use of /mnt/c et al from WSL2 for
compiling serenity. Namely, recommend against it as the performance
across the 9p file system protocol is terrible for IO heavy jobs.
This commit updates CLionConfiguration.md and NotesOnWSL.md so that
they comply with new build system. In addition to that, the WSL doc
is updated to include instructions to run qemu (and serenity) natively
on Windows, without needing an X-window server.