DOC: Fixing spaces before non param colons in docstrings.
- [x] closes #23780
- [x] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Hello @bk521234! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`pandas/core/algorithms.py`](https://github.com/bk521234/pandas/blob/cff44241e40cf6c95b13a0e6f5a682ded459e2c7/pandas/core/algorithms.py) !

 - There are no PEP8 issues in the file [`pandas/core/series.py`](https://github.com/bk521234/pandas/blob/cff44241e40cf6c95b13a0e6f5a682ded459e2c7/pandas/core/series.py) !

 - There are no PEP8 issues in the file [`pandas/io/excel.py`](https://github.com/bk521234/pandas/blob/cff44241e40cf6c95b13a0e6f5a682ded459e2c7/pandas/io/excel.py) !

 - There are no PEP8 issues in the file [`pandas/plotting/_core.py`](https://github.com/bk521234/pandas/blob/cff44241e40cf6c95b13a0e6f5a682ded459e2c7/pandas/plotting/_core.py) !

 - There are no PEP8 issues in the file [`pandas/plotting/_tools.py`](https://github.com/bk521234/pandas/blob/cff44241e40cf6c95b13a0e6f5a682ded459e2c7/pandas/plotting/_tools.py) !

 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=h1) Report
> :exclamation: No coverage uploaded for pull request base (`master@2af56d4`). [Click here to learn what that means](https://docs.codecov.io/docs/error-reference#section-missing-base-commit).
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/23805/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=tree)

```diff
@@            Coverage Diff            @@
##             master   #23805   +/-   ##
=========================================
  Coverage          ?   92.28%           
=========================================
  Files             ?      161           
  Lines             ?    51457           
  Branches          ?        0           
=========================================
  Hits              ?    47489           
  Misses            ?     3968           
  Partials          ?        0
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.68% <ø> (?)` | |
| #single | `42.31% <ø> (?)` | |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/23805/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `83.63% <ø> (ø)` | |
| [pandas/plotting/\_tools.py](https://codecov.io/gh/pandas-dev/pandas/pull/23805/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL190b29scy5weQ==) | `78.77% <ø> (ø)` | |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/23805/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `93.68% <ø> (ø)` | |
| [pandas/core/algorithms.py](https://codecov.io/gh/pandas-dev/pandas/pull/23805/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvYWxnb3JpdGhtcy5weQ==) | `95.11% <ø> (ø)` | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=footer). Last update [2af56d4...cff4424](https://codecov.io/gh/pandas-dev/pandas/pull/23805?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 :thumbsup: Thanks @bk521234 !