Imporve Wildcard Jinja2 Documentation.

[Tetrokun]

It was confusing trying to just get 1 element from a wildcard file, I found this worked for me, and I feel the documentation should be improved to be more clear for folks that aren't looking to generate a ton of prompts by using the provided for loop way of using wildcards

This is just a suggestion on how the documentation could be improved.

[adieyal]

Thanks for the PR. I think it's a bug that {{ choice("colours") }} doesn't do this. You can however use this syntax which I think is a little clearer:

{{ random_sample("__colours__") }}

What are your thoughts? I think that choice should be updated to work with wildcards.

[Tetrokun]

Agreed, I feel like having choice work with wildcards would be the best solution.

At the end of the day I think it matters most that this 'feature' works, and either random-sample or piping it to random() works. But your method is certainly cleaner., and easier to read.