Update documentation for SharedContext::maybe_collapsed_doc_value

Author: GuillaumeGomez

src/librustdoc/html/render/context.rs

@@ -135,8 +135,8 @@ impl SharedContext<'_> {
         Ok(())
     }
 
-    /// Based on whether the `collapse-docs` pass was run, return either the `doc_value` or the
-    /// `collapsed_doc_value` of the given item.
+    /// Returns the `collapsed_doc_value` of the given item if this is the main crate, otherwise
+    /// returns the `doc_value`.
     crate fn maybe_collapsed_doc_value<'a>(&self, item: &'a clean::Item) -> Option<String> {
         if self.collapsed { item.collapsed_doc_value() } else { item.doc_value() }
     }