Fix rectangle example

Author: jtran

rust/kcl-lib/std/sketch.kcl

@@ -265,8 +265,8 @@ export fn startProfile(
 ///
 /// ```
 /// exampleSketch = startSketchOn(-XZ)
-///   |> rectangle(corner = [0, 0], width = 10, height = 5)
-//    |> extrude(length = 2)
+/// rectSolid = rectangle(exampleSketch, corner = [0, 0], width = 10, height = 5)
+///   |> extrude(length = 2)
 /// ```
 @(impl = std_rust)
 export fn rectangle(