Generate a list of integers, with an optional step.
For example:
{{ 1|range:4 }}
Generates the list [1,2,3,4].
[1,2,3,4]
The second filter argument is the step size:
{{ 1|range:10:2 }}
Generates the list [1,3,5,7,9].
[1,3,5,7,9]