Make the function signature less prominent, add an early example to docs

Signed-off-by: Nick Cameron <nrc@ncameron.org>

docs/kcl-std/functions/std-sketch-patternTransform2d.md

@@ -8,16 +8,18 @@ layout: manual
 Just like `patternTransform`, but works on 2D sketches not 3D solids.
 
 ```kcl
-patternTransform2d(
-  @sketches: [Sketch; 1+],
-  instances: number(_),
-  transform: fn(number(_)): { },
-  useOriginal?: boolean,
-): [Sketch; 1+]
+// Each instance will be shifted along the X axis.
+fn transform(@id) {
+  return { translate = [4 * id, 0] }
+}
+
+// Sketch 4 circles.
+sketch001 = startSketchOn(XZ)
+  |> circle(center = [0, 0], radius = 2)
+  |> patternTransform2d(instances = 4, transform = transform)
+
 ```
 
-
-
 ### Arguments
 
 | Name | Type | Description | Required |
@@ -32,6 +34,17 @@ patternTransform2d(
 [`[Sketch; 1+]`](/docs/kcl-std/types/std-types-Sketch)
 
 
+### Function signature
+
+```kcl
+patternTransform2d(
+  @sketches: [Sketch; 1+],
+  instances: number(_),
+  transform: fn(number(_)): { },
+  useOriginal?: boolean,
+): [Sketch; 1+]
+```
+
 ### Examples
 
 ```kcl