Improve doc-string for `Image::alt_text`

crates/egui/src/widgets/image.rs

@@ -278,7 +278,8 @@ impl<'a> Image<'a> {
     }
 
     /// Set alt text for the image. This will be shown when the image fails to load.
-    /// It will also be read to screen readers.
+    ///
+    /// It will also be used for accessibility (e.g. read by screen readers).
     #[inline]
     pub fn alt_text(mut self, label: impl Into<String>) -> Self {
         self.alt_text = Some(label.into());
@@ -672,7 +673,7 @@ pub fn paint_texture_load_result(
     rect: Rect,
     show_loading_spinner: Option<bool>,
     options: &ImageOptions,
-    alt: Option<&str>,
+    alt_text: Option<&str>,
 ) {
     match tlr {
         Ok(TexturePoll::Ready { texture }) => {
@@ -697,9 +698,9 @@ pub fn paint_texture_load_result(
                 0.0,
                 TextFormat::simple(font_id.clone(), ui.visuals().error_fg_color),
             );
-            if let Some(alt) = alt {
+            if let Some(alt_text) = alt_text {
                 job.append(
-                    alt,
+                    alt_text,
                     ui.spacing().item_spacing.x,
                     TextFormat::simple(font_id, ui.visuals().text_color()),
                 );