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-math-abs.md

@@ -8,11 +8,20 @@ layout: manual
 Compute the absolute value of a number.
 
 ```kcl
-abs(@input: number): number
+myAngle = -120deg
+
+sketch001 = startSketchOn(XZ)
+  |> startProfile(at = [0, 0])
+  |> line(end = [8, 0])
+  |> angledLine(angle = abs(myAngle), length = 5)
+  |> line(end = [-5, 0])
+  |> angledLine(angle = myAngle, length = 5)
+  |> close()
+
+baseExtrusion = extrude(sketch001, length = 5)
+
 ```
 
-
-
 ### Arguments
 
 | Name | Type | Description | Required |
@@ -24,6 +33,12 @@ abs(@input: number): number
 [`number`](/docs/kcl-std/types/std-types-number) - A number.
 
 
+### Function signature
+
+```kcl
+abs(@input: number): number
+```
+
 ### Examples
 
 ```kcl