Documentation bug - wrong identity for default rehearsal mark format.

[Richard Shann]

I came across a documentation error:

http://lilypond.org/doc/v2.19/Documentation/notation/bars#rehearsal-marks


"The file ‘scm/translation-functions.scm’ contains the definitions of
format-mark-numbers (the default format),
 format-mark-box-numbers, format-mark-letters and
format-mark-box-letters." 

the default format is not format-mark-numbers, but format-mark-letters.

Richard Shann