enclose YAML strings containing % with quotes

Pygment uses the YAML 1.1 standard to parse YAML code being highlighted.
A string value cannot start with the percent sign in YAML 1.1 without
being quoted. To highlight the YAML code blocks propery, strings starting
with the percent sign are now enclosed in double quotes.
remove "..." from XML element tags

The ellipses were used as placeholders in XML element tags. Thus, the
XML wasn't well-formed and therefore would have never been rendered
properly.