Rename demo folder to project for generalizing the template usecase

Renames all references to the demo folder and changes it to "project"

.gitignore

@@ -3,20 +3,20 @@
 .godot/
 
 # Ignore library files but not the gdextension file
-demo/bin/*
-!demo/bin/android
-demo/bin/android/*
-!demo/bin/android/.gitkeep
-!demo/bin/linux
-demo/bin/linux/*
-!demo/bin/linux/.gitkeep
-!demo/bin/macos
-demo/bin/macos/*
-!demo/bin/macos/.gitkeep
-!demo/bin/windows
-demo/bin/windows/*
-!demo/bin/windows/.gitkeep
-!demo/bin/*.gdextension
+project/bin/*
+!project/bin/android
+project/bin/android/*
+!project/bin/android/.gitkeep
+!project/bin/linux
+project/bin/linux/*
+!project/bin/linux/.gitkeep
+!project/bin/macos
+project/bin/macos/*
+!project/bin/macos/.gitkeep
+!project/bin/windows
+project/bin/windows/*
+!project/bin/windows/.gitkeep
+!project/bin/*.gdextension
 .sconsign*.dblite
 
 # Ignore custom.py
@@ -59,4 +59,4 @@ compile_commands.json
 
 # Cmake
 cmake-build*
-CMakeUserPresets.json
+CMakeUserPresets.json