CLN: move pandas.formats -> pandas.io.formats
cc @TomAugspurger 

I *think* all of the styling should be ok with this move. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=h1) Report
> Merging [#16013](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/3119e909f7902a8d5f6d588e645e8744578afda9?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `98.03%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16013/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16013      +/-   ##
==========================================
- Coverage      91%   90.99%   -0.01%     
==========================================
  Files         153      153              
  Lines       50481    50481              
==========================================
- Hits        45938    45936       -2     
- Misses       4543     4545       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.76% <98.03%> (-0.01%)` | :arrow_down: |
| #single | `40.44% <76.47%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/formats/printing.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvcHJpbnRpbmcucHk=) | `88.17% <ø> (ø)` | |
| [pandas/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvaW50ZXJ2YWwucHk=) | `92.58% <0%> (ø)` | :arrow_up: |
| [pandas/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvbXVsdGkucHk=) | `96.7% <100%> (ø)` | :arrow_up: |
| [pandas/tseries/tdi.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvdGRpLnB5) | `90.37% <100%> (ø)` | :arrow_up: |
| [pandas/core/config\_init.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29uZmlnX2luaXQucHk=) | `95.34% <100%> (ø)` | :arrow_up: |
| [pandas/indexes/frozen.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvZnJvemVuLnB5) | `91.17% <100%> (ø)` | :arrow_up: |
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `81.87% <100%> (ø)` | :arrow_up: |
| [pandas/io/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2NvbW1vbi5weQ==) | `70.08% <100%> (ø)` | :arrow_up: |
| [pandas/core/groupby.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS5weQ==) | `92.03% <100%> (ø)` | :arrow_up: |
| [pandas/io/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2h0bWwucHk=) | `84.85% <100%> (ø)` | :arrow_up: |
| ... and [29 more](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16013?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/16013?src=pr&el=footer). Last update [3119e90...ac963ad](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=h1) Report
> Merging [#16013](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/3119e909f7902a8d5f6d588e645e8744578afda9?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `98.03%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16013/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16013      +/-   ##
==========================================
- Coverage      91%   90.99%   -0.01%     
==========================================
  Files         153      153              
  Lines       50481    50481              
==========================================
- Hits        45938    45936       -2     
- Misses       4543     4545       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.76% <98.03%> (-0.01%)` | :arrow_down: |
| #single | `40.44% <76.47%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/formats/printing.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvcHJpbnRpbmcucHk=) | `88.17% <ø> (ø)` | |
| [pandas/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvaW50ZXJ2YWwucHk=) | `92.58% <0%> (ø)` | :arrow_up: |
| [pandas/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvbXVsdGkucHk=) | `96.7% <100%> (ø)` | :arrow_up: |
| [pandas/tseries/tdi.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvdGRpLnB5) | `90.37% <100%> (ø)` | :arrow_up: |
| [pandas/core/config\_init.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvY29uZmlnX2luaXQucHk=) | `95.34% <100%> (ø)` | :arrow_up: |
| [pandas/indexes/frozen.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2luZGV4ZXMvZnJvemVuLnB5) | `91.17% <100%> (ø)` | :arrow_up: |
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `81.87% <100%> (ø)` | :arrow_up: |
| [pandas/io/common.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2NvbW1vbi5weQ==) | `70.08% <100%> (ø)` | :arrow_up: |
| [pandas/core/groupby.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS5weQ==) | `92.03% <100%> (ø)` | :arrow_up: |
| [pandas/io/html.py](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree#diff-cGFuZGFzL2lvL2h0bWwucHk=) | `84.85% <100%> (ø)` | :arrow_up: |
| ... and [29 more](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=tree-more) | |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16013?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/16013?src=pr&el=footer). Last update [3119e90...ac963ad](https://codecov.io/gh/pandas-dev/pandas/pull/16013?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
