Doc: mention tuplet-slur in Changes and in NR 1.2.1.2 "Tuplets"

Doc: mention tuplet-slur in Changes and in NR 1.2.1.2 "Tuplets"

See issue #5567 for David Nalesnik’s original patch.
Documenting why the bracket-visibility default behavior
isn’t suited to tuplet-slurs allows me to explicitely
point towards the relevant snippet for more clarity,
and to add a couple of additional internal references.

[lemzwerg, 2020-04-30 19:33:03]

LGTM, thanks!

https://codereview.appspot.com/559930043/diff/549940043/Documentation/notatio...
File Documentation/notation/rhythms.itely (right):

https://codereview.appspot.com/559930043/diff/549940043/Documentation/notatio...
Documentation/notation/rhythms.itely:275: @cindex tuplet slur
Add:

@cindex slur, for tuplets

https://codereview.appspot.com/559930043/diff/549940043/Documentation/notatio...
Documentation/notation/rhythms.itely:299: @cindex tuplet, visibility
Maybe modify this to

  @cindex tuplet bracket, visibility

since we already have this index entry.

Add:

  @cindex visibility of tuplet brackets

https://codereview.appspot.com/559930043/diff/549940043/Documentation/snippet...
File Documentation/snippets/controlling-tuplet-bracket-visibility.ly (right):

https://codereview.appspot.com/559930043/diff/549940043/Documentation/snippet...
Documentation/snippets/controlling-tuplet-bracket-visibility.ly:17: bracket),
@code{#'if-no-beam} (only print a bracket if there is no beam,
s/#'if-no-beam/'if-no-beam/

(for synchronization with the rest of the documentation)

[Valentin Villenave, 2020-05-07 12:05:52]

On 2020/04/30 19:33:03, lemzwerg wrote:
> LGTM, thanks!

Thanks Werner!  I added your suggestions and pushed it as
https://git.savannah.gnu.org/cgit/lilypond.git/commit/?id=ee56da0f7a68cb6d6c5...

V.