[doc] Add python docstring for gui.py (#2604)
[doc] Add python docstring for gui.py (#2604)

* [doc] Add python doc for gui.py.

* [doc] Add python docstring for gui.py

* Update python/taichi/misc/gui.py

* resolve conversation

* resolve conversation

Co-authored-by: ljcc0930 <953310eb562334e499fc2456ce61432ad91acebf@qq.com>
yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi