DOC: update examples in MonthBegin/MonthEnd to use rollbackward/rollforward
- [ ] closes #52106
updated docstring of pandas.offsets.MonthBegin, pandas.offsets.MonthEnd, pandas.offsets.BMonthBegin, pandas.offsets.BMonthEnd
the output of the `validate_docsctrings.py`  is similar to the below output as follows
```
################################################################################
#################### Docstring (pandas.offsets.MonthBegin)  ####################
################################################################################

DateOffset of one month at beginning.

Examples
--------
>>> ts = pd.Timestamp(2022, 1, 1)
>>> ts + pd.offsets.MonthBegin()
Timestamp('2022-02-01 00:00:00')

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

2 Errors found:
        No extended summary found
        See Also section not found
```
Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
git checkout 2.0.x
git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
git cherry-pick -x -m1 4bf60ac2bab5878c1a0f640ab826df77a77f7e98
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
git commit -am 'Backport PR #52161: Docs/update issue 52106'
```

4. Push to a named branch:

```
git push YOURFORK 2.0.x:auto-backport-of-pr-52161-on-2.0.x
```

5. Create a PR against branch 2.0.x, I would have named this PR:

> "Backport PR #52161 on branch 2.0.x (Docs/update issue 52106)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the `Still Needs Manual Backport` label once the PR gets merged.

If these instructions are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 @pranav-ravuri there's one more related one, in case you wanted to take this one on https://github.com/pandas-dev/pandas/issues/52169 Hi @MarcoGorelli there seems to be conflict, but I did not understand what it is? And how could I have avoided it? the conflict is only when backporting to version 2.0 (from which the next stable docs will be built) - you did everything right, it's just that not everything gets backported, so conflicts creep in sometimes