message: Fix minor typo checkou -> checkout
diff: @@ -7,4 +7,4 @@ Rough manual steps:
  3. Build for x64 and set `CMAKE_INSTALL_PREFIX` to a `x64` subfolder here.
  4. Optionally build for x86 and install to a `x86` subfolder.
  -On linux install to `linux64` or `linux32` (to allow sharing a checkou with windows).
  +On linux install to `linux64` or `linux32` (to allow sharing a checkout with windows).
  