Add option to specify height and/or width of plot axes.

[NevPalmer]

Add option to specify height and/or width of plot axes.
Although the output is a scalable vector graphic (SVG) all the features (text, line widths, etc) are scaled and distorted proportionally so that enlarging the output from the default size does not clarify any detail it simply plots the same image larger on the screen.
As an example, the image below shows the same plot for MAVL displayed at the default size (800x270) and a specified size of (800x800) in an attempt to exaggerate the y-scale. This only distorts the image without improving the visible detail because all line widths and font sizes are scaled proportionately.

[elidana]

this can be done by using the yrange option (introduced in aa73b7b) and maybe using the scatter type as plotting style

@NevPalmer , can you please check if the following URL does the trick for you and fix your problem?
https://fits.geonet.org.nz/plot?type=scatter&sites=LI.MAVL&typeID=n&yrange=-200,100

Thanks!