Fix styling of the tables

[jorisvandenbossche]

See eg https://dev.pandas.io/pandas-sphinx-theme/reference/io.html

We might need to remove some old custom styling (from nature), and ensure that bootstrap's tables are used. But those might again require some styling to fit for autosummary tables etc

[jorisvandenbossche]

So the normal tables are fine (and now look good as bootstrap tables after #21), but the autosummary generated tables have some problems:

(https://dev.pandas.io/docs/reference/frame.html)

The problem is in autosummary defining a colgroup in the generated html:

<table class="longtable table">
  <colgroup>
    <col style="width: 10%">
    <col style="width: 90%">
  </colgroup>
  <tbody>
...

and for some reason all existing sphinx themes I looked at handle this fine (basically ignore it?), but bootstrap wants to follow it (although it also expands somewhat when needed, because sometimes it is more than 10%, see picture above).

[jreback]

random issue here: https://dev.pandas.io/docs/user_guide/reshaping.html

pivoting with single aggregations (table not rendering in the note)

[jorisvandenbossche]

@jreback that's broken in the old docs as well (https://pandas.pydata.org/pandas-docs/stable/user_guide/reshaping.html#pivoting-with-single-aggregations), so probably rather an issue with the rst formatting. Will open an issue on the pandas side.

[jorisvandenbossche]

From #27: we might want to have "striped" tables as a default. Either we add some css to apply that to all tables, or we can ensure in the rst to add the table-striped class.

[12rambau]

This is an old issue, the current table display looks like this:

Do you still think that having them striped is necessary?

[choldgraf]

In my opinion, we can close this one and re-open a new one if somebody else reports a problem, since the style has changed a decent amount