DOC: Improve docstring of Timedelta.delta
- [ ] closes #xxxx
- [ ] tests added / passed
- [X] passes `git diff upstream/master -u -- "*.pyx" | flake8 --diff`
- [ ] whatsnew entry

```
################################################################################
###################### Docstring (pandas.Timedelta.delta) ######################
################################################################################

Return the timedelta in nanoseconds (ns), for internal compatibility.

Returns
-------
int
    Timedelta in nanoseconds.

Examples
--------
**Using string input**

>>> td = pd.Timedelta('1 days 42 ns')
>>> td.delta
86400000000042

>>> td = pd.Timedelta('3 s')
>>> td.delta
3000000000

>>> td = pd.Timedelta('3 ms 5 us')
>>> td.delta
3005000

**Using integer input**

>>> td = pd.Timedelta(42, unit='ns')
>>> td.delta
42

################################################################################
################################## Validation ##################################
################################################################################

Errors found:
	No extended summary found
	See Also section not found
```
i did some looking at how to `git` rid of (pun intended) a bunch of the changes that are cluttering up the works.
think I am gonna just close this, try to submit a new pull request starting with a clean slate.
See PR #21138 