TEI bug causes missing valList items, so we need to supply them

[martindholmes]

There is a bug in the TEI Stylesheets which means that only "semi" <valList>s get expanded into documentation when an attribute is included by means of a with@atts. We need to work around this problem, either by supplying our own post-processing that retrieves missing rendered content from the appropriate spec table, or manually include that information in cases where it's especially important (such as the description ofscoringAlgorithm/@name`).