DOC: Add examples to Series operators (#24589)
Further work on #24589.  PR #25524 added examples for many operations but not `pandas.Series.eq`, `pandas.Series.ne`, `pandas.Series.gt`, `pandas.Series.ge`, `pandas.series.le`, and `pandas.series.lt`.  This adds examples for those.

`pandas.Series.divmod` is still missing an example as discussed in #25524.
