DOC: Added examples to pandas.concat documentation
I've added two simple examples to the ``pd.concat`` documentation. I've also done a very small amount of clean up on the rest of the docstring.

 - [x] passes ``git diff upstream/master | flake8 --diff``
That's fine by me. I'll add a link to that walkthrough and a wider array of
examples. I'll aim for the new examples to be more discrete and less
holistic than the walkthrough.

On Sun, Jan 1, 2017, 10:46 AM Jeff Reback <notifications@github.com> wrote:

> *@jreback* commented on this pull request.
> ------------------------------
>
> In pandas/tools/merge.py
> <https://github.com/pandas-dev/pandas/pull/15028#pullrequestreview-14816434>
> :
>
> >      Returns
>      -------
>      concatenated : type of objects
> +
> +    Notes
> +    -----
>
> if you are going to add examples, then this needs to be more complete,
> using examples from here:
> http://pandas.pydata.org/pandas-docs/stable/merging.html#concatenating-objects
>
> certainly not all of these, but a quick selection (as well as having this
> link would be fine).
>
> —
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>
 ## [Current coverage](https://codecov.io/gh/pandas-dev/pandas/pull/15028?src=pr) is 84.75% (diff: 100%)
> Merging [#15028](https://codecov.io/gh/pandas-dev/pandas/pull/15028?src=pr) into [master](https://codecov.io/gh/pandas-dev/pandas/branch/master?src=pr) will decrease coverage by **0.01%**

```diff
@@             master     #15028   diff @@
==========================================
  Files           145        145          
  Lines         51131      51146    +15   
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
+ Hits          43345      43350     +5   
- Misses         7786       7796    +10   
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [3662413...c58f9f8](https://codecov.io/gh/pandas-dev/pandas/compare/366241386282272328333256b6e267a68f8133a4...c58f9f8c40ed525f05de2cb124ab7e5f1dbe7b9d?src=pr) @jorisvandenbossche and @jreback, I believe I've made the changes you've asked for. Please let me know if there's anything more I can do.  @jorisvandenbossche I believe I have made the changes you've requested. Please let me know if there's more I can do.  @palewire Thanks!