Add Skeleton component documentation

docs/library/other/skeleton.md

@@ -0,0 +1,27 @@
+---
+description: Skeleton, a loading placeholder component for content that is not yet available.
+components:
+    - rx.skeleton
+---
+
+```python exec
+import reflex as rx
+```
+
+# Skeleton (loading placeholder)
+
+`Skeleton` is a loading placeholder component that serves as a visual placeholder while content is loading.
+It is useful for maintaining the layout's structure and providing users with a sense of progression while awaiting the final content.
+
+```python demo
+rx.vstack(
+    rx.skeleton(rx.button("button-small"), height="10px"),
+    rx.skeleton(rx.button("button-big"), height="20px"),
+    rx.skeleton(rx.text("Text is loaded."), loading=True,),
+    rx.skeleton(rx.text("Text is already loaded."), loading=False,),
+),
+```
+
+When using `Skeleton` with text, wrap the text itself instead of the parent element to have a placeholder of the same size.
+
+Use the loading prop to control whether the skeleton or its children are displayed. Skeleton preserves the dimensions of children when they are hidden and disables interactive elements.