feat: Implement core functionality for DTC C/C++ IDE

- Added ProjectManager class to handle project operations including opening, closing, building, and running projects.
- Introduced SyntaxHighlighter class for syntax highlighting in C and C++ files.
- Developed TerminalWidget for command execution and output display.
- Created TextEditor with line numbering and auto-indentation features.
- Established main application entry point in main.cpp.
- Designed UI layout for MainWindow using Qt Designer.

.gitignore

@@ -0,0 +1,27 @@
+# Build directories
+build/
+dist/
+bin/
+
+# Qt creator files
+*.user
+*.pro.user
+
+# Executables
+*.app
+*.dmg
+*.exe
+
+# OS generated
+.DS_Store
+*.swp
+*.swo
+
+# CMake
+CMakeCache.txt
+CMakeFiles/
+Makefile
+cmake_install.cmake
+
+# VSCode
+.vscode/