* add predictTags and printDocStr for tags prediction

* add predictTags and printDocStr for tags prediction

* add predictTags and printDocStr for tags prediction

* Add predictTags and printDocStr for tags prediction

* added pybind11 binding for predictTags method

* added test case for predictTags

* add data to train/test tag prediction

* added documentation for predictTags in README

* added documentation for predictTags in README