cppclean: add page (#1745)

pages/common/cppclean.md

@@ -0,0 +1,19 @@
+# cppclean
+
+> Find unused code in C++ projects.
+
+- Run in a project's folder:
+
+`cppclean {{path/to/project}}`
+
+- Run on a project where the headers are in the "inc1/" and "inc2/" folders:
+
+`cppclean {{path/to/project}} --include-path={{inc1}} --include-path={{inc2}}`
+
+- Run on a specific file "main.cpp":
+
+`cppclean {{main.cpp}}`
+
+- Run on the current directory, excluding the "build" directory:
+
+`cppclean {{.}} --exclude={{build}}`