chore: update build script

- change project layout for better understanding.
- update build script for more close to standard cmake way.

.gitignore

@@ -1,22 +1,25 @@
-# -------------------- Personal --------------------
+## ======== Personal ========
+# Ignore build resources
+out/
+build/
+install/
+extern/
+temp/
+
 # Ignore all possible test used Virtools files
 *.nmo
 *.cmo
 *.nms
 *.vmo
 
-# Ignore CMake generated version header
-LibCmo/VTVersion.hpp
-
-# Ignore temporary Visual Studio files and folders
-temp/
-out/
+# Ignore CMake generated stuff
+LibCmo/LibCmo/VTVersion.hpp
 CMakeSettings.json
 
-# -------------------- VSCode --------------------
+## ======== VSCode ========
 .vscode/
 
-# -------------------- CMake --------------------
+## ======== CMake ========
 CMakeLists.txt.user
 CMakeCache.txt
 CMakeFiles
@@ -29,7 +32,7 @@ compile_commands.json
 CTestTestfile.cmake
 _deps
 
-# -------------------- Visual Studio --------------------
+## ======== Visual Studio ========
 ## Ignore Visual Studio temporary files, build results, and
 ## files generated by popular Visual Studio add-ons.
 ##