message: Add documentation to populate_string_maps param
diff: @@ -215,6 +215,9 @@ class VerilogProject {
  typedef file_set_type::iterator iterator;
  typedef file_set_type::const_iterator const_iterator;
  + // Constructor. Note that `populate_string_maps` (populating internal string
  + // view maps) fragments the class's usage. Enabling it prevents removing files
  + // from the project (which is required for Kythe facts extraction).
  VerilogProject(absl::string_view root,
  const std::vector<std::string>& include_paths,
  absl::string_view corpus = "",
  