Docs: IR: improve docs for ly:add-option

diff --git a/lily/program-option-scheme.cc b/lily/program-option-scheme.cc
index dca049028860bd85bdca04903588d5cf91a505ee..bfa5d09934abed2ba5b1df685f6282909a2a99c3 100644 (file)
--- a/lily/program-option-scheme.cc
+++ b/lily/program-option-scheme.cc
@@ -183,7 +183,8 @@ LY_DEFINE (ly_option_usage, "ly:option-usage", 0, 0, 0, (),
 
 LY_DEFINE (ly_add_option, "ly:add-option", 3, 0, 0,
           (SCM sym, SCM val, SCM description),
-          "Add a program option @var{sym} with default @var{val}.")
+          "Add a program option @var{sym}.  @var{val} is the default"
+          " value and @var{description} is a string description.")
 {
   if (!option_hash)
     option_hash = scm_permanent_object (scm_c_make_hash_table (11));