docs: Improve Issue Templates

ci: Add `go vet` to `lint`

fix: Fix for preferring smaller label counts when unit is used

This change fixes a regression introduced in the prior change (v0.5.12). The improved unit label count / span logic failed to have a preference for more labels. Resulting in cases where two labels are equally good as charts where every value is labeled.
This updates the conditional to prefer higher label counts when the delta from the padded label count is the same.

fix: Range better handling for determining the max when a unit is spe…

…cified

The change in 7d38925 fixed an infinite loop, but resulted in potentially a very large max range calculation, which would take forever to render.

This redos that logic using a mechanism which loops less, while still doing a comparision to pick the best possible result.

fix: doughnut_chart center to white ONLY if color is zero

fix: Fix stacked category axis spacing (bar charts)

Our prior logic in `range` for producing a category axis would use the series names for labels. This is not correct, instead the axis should represent the data span.

This was most obvious in bar charts when the series is stacked. It would show the bar as being pushed to the edge for each series (that was instead stacked instead of beside).

feat: Add NewXChartOptionWithSeries to provide chart defaults with a …

…given series data

fix: Stacked charts should only have the mininum subtracted to at low…

…est 0

We don't want this adjustement to push into negative axis ranges.

fix: Small stacked series always shown in stack

Prior to this change the value range may result in the range minimum value matching the series miniumum value. This results in series bars / lines which normally would meet the X axis, but in a stacked series it results in the series just being hidden.

In this change, when a series is stacked we just subtract one from the mininum value, resulting in even the smallest series representing at least "one" value worth of space.

docs: Add godocs for chart option and other structs