Prerequisites for isogram practice exercise

[AnishDe12020]

I have added the prerequisites for the isogram practice exercise.

references #984

[github-actions]

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[junedev]

Same as for acronym, I don't understand the selection here. I would have expected strings and regular expressions.

[AnishDe12020]

This exercise can be solved without regular expressions (although it will make it a bit longer). Also, I have added arrays because sets are used in the solving of this (my solution as well as top solutions which solve the latest version of the solution use it). I can add regular expressions if required.

[SleeplessByte]

https://exercism.org/tracks/javascript/exercises/isogram/solutions/junedev
https://exercism.org/tracks/javascript/exercises/isogram/solutions/sleeplessbyte

Here are ours.

I did check the first few community solutions, and it seems that each one uses regular expressions. So even though you can solve it without, I think it should be included. The majority of one liners don't use arrays, so I don't think it's a prerequisite to finish the exercise, but I can see how you must be able to "see" the string as an "array of characters" to solve it. I would be okay leaving arrays in.

[AnishDe12020]

Cool, I have added it in 1a7e3f1

[junedev]

@AnishDe12020 Looks like there is a small mistake. You added something to "topics" which is not used anymore.

[AnishDe12020]

I got a bit confused actually. Nevertheless, I have fixed it in 39e6035. Do let me know if it is fine

[junedev]

I noticed this comment actually belongs to line 805.

[AnishDe12020]

Yeah, I have fixed it there itself.