Add missing defaults for function round().

Author: stefano-ottolenghi

modules/ROOT/pages/functions/mathematical-numeric.adoc

@@ -259,8 +259,8 @@ A random number is returned.
 | *Description* 3+| Returns the value of a rounded number, optionally using a specified precision and rounding mode.
 .4+| *Arguments* | *Name* | *Type* | *Description*
 | `value` | `FLOAT` | A value to be rounded.
-| `precision` | `INTEGER \| FLOAT` | The rounding precision.
-| `mode` | `STRING` | A precision rounding mode (`UP`, `DOWN`, `CEILING`, `FLOOR`, `HALF_UP`, `HALF_DOWN`, `HALF_EVEN`).
+| `precision` | `INTEGER \| FLOAT` | The rounding precision (default: `0`).
+| `mode` | `STRING` | A precision rounding mode (`UP`, `DOWN`, `CEILING`, `FLOOR`, `HALF_UP`, `HALF_DOWN`, `HALF_EVEN`) (default: `UP`).
 | *Returns* 3+| `FLOAT`
 |===