v3.3.11 tasks

[eeholmes]

• Create RStudio Cloud badge so users can try without installing anything
• Add some color examples with html colors, e.g. for colorbox; show how to define in header; (note mostly done)
• Need to allow -top spec for coverpage elements; check that both top and bottom are not spec-ed
• Complain if colorbox-fill used.
• warn user if they pass in fontsize plus a font sizing in fontstyle
• probably should stop using large, tiny etc in fontstyle
• Add separate documentation section for the title, author and affiliation styles
• need a way to get rid of the fontstyle author-fontstyle: false confusing if you use a theme but can't get rid of the font-style.
• Get rid of page-html-color . Instead define colors in header.
• Add instructions for fonts
• Add instructions for getting rid of that QT font file.