fix(docs): replace outdated links in the Astro.csp JSDocs

[ArmandPhilippot]

Changes

• Replaces the links used as reference for the Astro.csp utilities. These links were not updated when the feature became stable, and the old experimental feature page redirects to the configuration reference and not to the API reference.
• Standardize how JSDoc comments begin. Most start with a definition/a present tense verb, but that wasn't the case for a few. (a nit while I was there...)

Testing

N/A

Docs

This is docs; changeset added as we fix something in the docs.

[codspeed]

Merging this PR will not alter performance

✅ 21 untouched benchmarks

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_{Comparing armand/fix-astro-docs-links (91386c2) with main (95d5d16)¹}

Footnotes

1. No successful run was found on main (e4f8f46) during the generation of this report, so 95d5d16 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩