Add vertical selection in interactive plot session

[smoia]

At the moment, the "selection" of peaks in the interactive plot session can only be done by dragging and selecting an area horizontally - which is great for some signals and purposes, but not for all (e.g. CO2 peak detection for CVR mapping). In #26, there is already the idea of adding single-click actions to remove peaks (which would help immensely). Another way to improve this practice would be to to drag and select a vertical section of the plot. This would again help in cases such as CO2 and CVR mapping, since peaks that might be detected erroneously but are clearly below a certain threshold could be removed manually, without having to re-run the peak detection.

[mmcky]

@shlff maybe in this case we should update our latex figure placement rules

https://www.sphinx-doc.org/en/master/latex.html

'figure_align'
Latex figure float alignment. Whenever an image doesn’t fit into the current page, it will be ‘floated’ into the next page but may be preceded by any other text. If you don’t like this behavior, use ‘H’ which will disable floating and position figures strictly in the order they appear in the source.

Default: 'htbp' (here, top, bottom, page)

maybe we should switch on H in this case (in _config.yml) so they are always in place.

[shlff]

This issue still exists. Please find the newest build:

https://python.quantecon.org/_pdf/quantecon-python.pdf