GDP -- Revised second draft of Fretted strings

[Carl D. Sorensen]

Dear Lilypond Users and Developers,

We're pleased to announce a revised second draft of NR 2.4 Fretted strings.

This draft includes the new predefined-fretboards functionality that enables
transposable guitar fret diagrams.

Please proofread this section carefully, and try an example or two to see if
the documentation is clear (especially 2.4.1.5 through 2.4.1.7).

As always, the GDP documentation can be found at
http://kainhofer.com/~lilypond/Documentation/user/lilypond/index.html

Thanks in advance for your reviews.  Your careful reviews will help the
quality of the documentation match the quality of LilyPond output.

Carl Sorensen