[Mixed Juices] Fix hints' reference to MDN's fall-though section

[anym0us]

MDN switch documentation has been updated some time ago, so section references has been changed.

This PR fixes the reference to fall-through section in tasks' hints.

Screenshot

Proposed change

Currently	Suggested
https://eveloper.mozilla.org/en-US/docs/.../ switch#what_happens_if_i_forgot_a_break	https://developer.mozilla.org/en-US/docs/.../ switch#breaking_and_fall-through

[github-actions]

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[anym0us]

@SleeplessByte Hello! 👋 Please could you have a look, once you have a minute? 🙏 I've re-created a PR.