📚 docs(randrange): Add function signature and detailed description.

src/api/randrange.js

@@ -1,12 +1,24 @@
 import randint from './randint.js';
 
 /**
- * Return a randomly selected element from range(start, stop, step).
+ * Pick an element from range(start, stop, step) uniformly at random.
+ *
+ * Return an element from range(start, stop, step) selected uniformly at random.
+ * If step is positive, this set corresponds to
+ * {x: x in [start, stop[ AND x % step = 0}.
+ * If step is negative, the range has to be given in reverse order, that is,
+ * largest value first, smallest value second. Both the starting value and the
+ * step value are optional. By default the starting value is <code>0</code>.
+ * The default for the step value is <code>1</code>.
+ *
+ * TODO: Handle empty ranges.
+ *
+ * @param {number} [start=0] - The starting value.
+ * @param {number} stop - The stopping value.
+ * @param {number} [step=1] - The step value.
+ * @return {number} The picked element.
  */
-
 const randrange = (start, stop, step) => {
-	// TODO handle empty ranges
-
 	if (stop === undefined) return randint(0, start);
 	if (step === undefined) step = 1;