Fix issue where 'Read less' would appear on non-collapsible text. (#119)

* Fix issue where 'Read less' would appear on non-collapsible text.

* Change screenshots

Author: fornewid

readmore-foundation/screenshots/BasicReadMoreTextScreenshotTest.AnnotatedString_short.all_expanded.png

@@ -247,7 +247,7 @@ private fun CoreReadMoreText(
     val currentText = buildAnnotatedString {
         if (expanded) {
             append(text)
-            if (readLessTextWithStyle.isNotEmpty()) {
+            if (state.isCollapsible && readLessTextWithStyle.isNotEmpty()) {
                 append(' ')
                 if (toggleArea == ToggleArea.More) {
                     withLink(