Added fs.is_newer function to filesystem library

include/lua_filesystem.h

@@ -20,6 +20,11 @@ int lua_fs_forall_dir_next(lua_State* L);
 int lua_fs_foreach_dir_dtor(lua_State* L);
 int lua_fs_forall_dir_dtor(lua_State* L);
 
+// Returns true when a is newer than b. If b does not exist it returns true. If a does not exist it returns false
+// boolean | table<boolean> function fs.is_newer(path_a: string | number, path_b: string | table[string])
+int lua_fs_is_newer(lua_State* L);
+// table<string> | nil function fs.filter_newer(path_a: string | number, path_b: string | table[string])
+int lua_fs_filter_newer(lua_State* L);
 
 // number | nil function fs.last_modified(path: string)
 int lua_fs_last_modified(lua_State* L);