Documentation Howto section sidebar is getting busy, so needs review.

[jhkrug]

Over the past few months, the range of content has expanded in the Howtos section. Recently @viccuad rearranged this in, more or less, common tasks order, so most common to less common.

Due to the section's busyness, it's worth reviewing this to see if subsections are now also needed, with the subsections providing further topic grouping.