Unity only generates project files in the top-level directory.
However, the current .gitignore will ignore all project files even
if they were not generated by Unity.
It is sometimes necessary to include non-Unity project files for
level editors or other utility projects that have been added to the
repository.
[Oo]bj/
# Autogenerated VS/MD solution and project files
-*.csproj
-*.unityproj
-*.sln
-*.suo
-*.user
+/*.csproj
+/*.unityproj
+/*.sln
+/*.suo
+/*.user