plot: Improve tick documentation (#269)

Improve documentation a bit.

src/lib/plot.typ

@@ -54,13 +54,13 @@
 ///
 /// The following options are supported per axis
 /// and must be prefixed by `<axis-name>-`, e.G.
-/// `x-min: 0`.
+/// `x-min: 0` or `y-label: [y]`.
 /// #box[
 ///   - label (content): Axis label
 ///   - min (int): Axis minimum value
 ///   - max (int): Axis maximum value
-///   - tick-step (float): Distance between major ticks
-///   - minor-tick-step (float): Distance between minor ticks
+///   - tick-step (none, float): Distance between major ticks (or no ticks if none)
+///   - minor-tick-step (none, float): Distance between minor ticks (or no ticks if none)
 ///   - ticks (array): List of ticks values or value/label
 ///                    tuples. Example `(1,2,3)` or `((1, [A]), (2, [B]),)`
 ///   - format (string): Tick label format, `"float"`, `"sci"` (scientific)
@@ -71,7 +71,7 @@
 ///                         - `"minor"`: Enable minor tick grid
 ///                         - `"both"`: Enable major & minor tick grid
 ///                         - `false`: Disable grid
-///   - unit (content): Tick label suffix
+///   - unit (none, content): Tick label suffix
 ///   - decimals (int): Number of decimals digits to display for tick labels
 /// ]
 ///