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-log.md

@@ -8,15 +8,16 @@ layout: manual
 Compute the logarithm of the number with respect to an arbitrary base.
 
 ```kcl
-log(
-  @input: number,
-  base: number(_),
-): number
-```
+exampleSketch = startSketchOn(XZ)
+  |> startProfile(at = [0, 0])
+  |> line(end = [log(100, base = 5), 0])
+  |> line(end = [5, 8])
+  |> line(end = [-10, 0])
+  |> close()
 
-The result might not be correctly rounded owing to implementation
-details; `log2` can produce more accurate results for base 2,
-and `log10` can produce more accurate results for base 10.
+example = extrude(exampleSketch, length = 5)
+
+```
 
 ### Arguments
 
@@ -29,6 +30,20 @@ and `log10` can produce more accurate results for base 10.
 
 [`number`](/docs/kcl-std/types/std-types-number) - A number.
 
+### Description
+
+The result might not be correctly rounded owing to implementation
+details; `log2` can produce more accurate results for base 2,
+and `log10` can produce more accurate results for base 10.
+
+### Function signature
+
+```kcl
+log(
+  @input: number,
+  base: number(_),
+): number
+```
 
 ### Examples