Re: Doc: improve doc on markup command writing (issue157133)

[Ian Hulin]

Nicolas,
I'm now having similar problems on Rietveld as Graham.

First five lines of your docstring in scm/markup.scm in the 
property-bind macro should say:

"Search properties in `props', and bind each property symbol to a
corresponding value, or to a default if a value is not found.
 props: a list of associative lists
 properties-and-default-values: a list of (property default-value) or
(property) elements. If a default value is not provided, #f is used 
instead.