Run cmake-init and setup flake.nix and default.nix

cmake/folders.cmake

@@ -0,0 +1,21 @@
+set_property(GLOBAL PROPERTY USE_FOLDERS YES)
+
+# Call this function at the end of a directory scope to assign a folder to
+# targets created in that directory. Utility targets will be assigned to the
+# UtilityTargets folder, otherwise to the ${name}Targets folder. If a target
+# already has a folder assigned, then that target will be skipped.
+function(add_folders name)
+  get_property(targets DIRECTORY PROPERTY BUILDSYSTEM_TARGETS)
+  foreach(target IN LISTS targets)
+    get_property(folder TARGET "${target}" PROPERTY FOLDER)
+    if(DEFINED folder)
+      continue()
+    endif()
+    set(folder Utility)
+    get_property(type TARGET "${target}" PROPERTY TYPE)
+    if(NOT type STREQUAL "UTILITY")
+      set(folder "${name}")
+    endif()
+    set_property(TARGET "${target}" PROPERTY FOLDER "${folder}Targets")
+  endforeach()
+endfunction()