chore: mark unsupported features in linear progress theming API

PiperOrigin-RevId: 483445711

Author: patrickrodee

packages/mdc-linear-progress/_linear-progress-theme.scss

@@ -35,6 +35,7 @@ $height: 4px;
 
 $custom-property-prefix: 'linear-progress';
 
+// TODO(b/254889918): Support all linear progress tokens.
 $light-theme: (
   active-indicator-color: theme-color.$primary,
   track-color: $baseline-buffer-color,

packages/mdc-linear-progress/_linear-progress.scss

@@ -442,6 +442,7 @@
       // Normally the buffer dots start from the left and overflow to the right.
       // We rotate by 180deg so that the buffer dots start on the right when
       // in non-reversed mode and overflow to the left.
+      // TODO(b/254896788): Remove hardcoded translateX.
       transform: rotate(180deg) translateX(-10px);
     }
   }