Fix Row::ends_with_newline docs, explain skipping of last galley row

crates/epaint/src/text/fonts.rs

@@ -807,6 +807,9 @@ impl GalleyCache {
             let current_offset = emath::vec2(0.0, merged_galley.rect.height());
 
             let mut rows = galley.rows.iter();
+            // As documented in `Row::ends_with_newline`, a '\n' will always create a
+            // new `Row` immediately below the current one. Here it doesn't make sense
+            // for us to append this new row so we just ignore it.
             if i != galleys.len() - 1 && !galley.elided {
                 let popped = rows.next_back();
                 debug_assert_eq!(popped.unwrap().row.glyphs.len(), 0);

crates/epaint/src/text/text_layout_types.rs

@@ -581,7 +581,7 @@ pub struct Row {
     pub visuals: RowVisuals,
 
     /// If true, this [`Row`] came from a paragraph ending with a `\n`.
-    /// The `\n` itself is omitted from [`glyphs`].
+    /// The `\n` itself is omitted from [`Self::glyphs`].
     /// A `\n` in the input text always creates a new [`Row`] below it,
     /// so that text that ends with `\n` has an empty [`Row`] last.
     /// This also implies that the last [`Row`] in a [`Galley`] always has `ends_with_newline == false`.