feat(Timestamp): add the from_datetime method

To update the current Timestamp instance based on a datetime or date object.

I've also included a set_datetime method to OrgTime

feat: add activate and deactivate methods to TimeRange and OrgTime

I need it in a program I'm making
refactor: Create the Time type hint

I had to move the parse_time and parse_org_time_range below OrgTime
because it used the Time type hint and the Time type hint needed the
other two

style: reformat the code following black

style: Add some type hints and docstrings

style: remove unused imports

tests: Correct some mypy errors

org_rw/types.py

@@ -1,6 +1,7 @@
 import re
 from typing import List, TypedDict
 
+
 class HeadlineDict(TypedDict):
     linenum: int
     orig: re.Match