Add prerequisites for practice exercises

[TomPradat]

Could I please have an hacktoberfest label 🙏 ?

This solves 4 exercises in the issue #984

[github-actions]

Dear TomPradat

Thank you for contributing to the JavaScript track on Exercism! 💙
You will see some automated feedback below 🤖. It would be great if you can make sure your PR covers those points. This will save your reviewer some time and your change can be merged quicker.

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_{Automated comment created by PR Commenter 🤖.}

[TomPradat]

Here is my solution : https://exercism.org/tracks/javascript/exercises/matching-brackets/solutions/TomPradat

I've seen many solutions with conditional switches and I prefer it to regexps ones. Also I've added arrays because I think this is good exercise for 'stack' type solutions

[TomPradat]

Here is my solution : https://exercism.org/tracks/javascript/exercises/series/solutions/TomPradat

[TomPradat]

Here is my solution : https://exercism.org/tracks/javascript/exercises/grep/solutions/TomPradat

[TomPradat]

Here is my solution : https://exercism.org/tracks/javascript/exercises/spiral-matrix/solutions/TomPradat

Most solutions don't use switch conditionals so I didn't add it

[SleeplessByte]

I've cross referenced your comments to the top community solutions and I agree. Thank you, this is a great addition.