add gitignore

From https://github.com/github/gitignore/blob/main/C%2B%2B.gitignore + exclude IDE dirs

Author: ajay-mk

.gitignore

@@ -0,0 +1,45 @@
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Linker files
+*.ilk
+
+# Debugger Files
+*.pdb
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+# debug information files
+*.dwo
+
+# IDEs
+*.idea
+*.vscode