Improve equation reference example (#6481)

crates/typst-library/src/model/reference.rs

@@ -91,16 +91,13 @@ use crate::text::TextElem;
 /// #show ref: it => {
 ///   let eq = math.equation
 ///   let el = it.element
-///   if el != none and el.func() == eq {
+///   // Skip all other references.
+///   if el == none or el.func() != eq { return it }
 ///   // Override equation references.
 ///   link(el.location(), numbering(
 ///     el.numbering,
 ///     ..counter(eq).at(el.location())
 ///   ))
-///   } else {
-///     // Other references as usual.
-///     it
-///   }
 /// }
 ///
 /// = Beginnings <beginning>