Fix code generation (see #1008)

This is a duplicate of f396183e2aff0760665767377eb336e385c158ff.  Rather than removing documentation to work with the tools or waiting for that ticket to be reviewed, I'm adding the same here.
minZoom is not a supported property of ol.tilegrid.XYZOptions
Adding XYZOptions to objectliterals.jsdoc

I remain confused about when to use the @exportClass annotation and when to use the @exportSymbol.  osmsource.exports seems to get away with simply @exportSymbol, but many other sources use @exportProperty.