Introduce a script to index the static docs HTML files generated by Next.js into Algolia.

It's a migration from the Gatsby solution, which relied on the gatsby-plugin-algolia here

The record generation logic is reused as is, with two notable changes:

1. We manually feed the HTML files to the record generation function
2. We manually upload the records to Algolia

Required environment variables before the merge (repo secrets):

• ALGOLIA_APP_ID=OOK48W9UCL
• ALGOLIA_API_KEY: The write API key
• ALGOLIA_INDEX_PREFIX: (sentry-), which will show up as sentry-docs (index name) on Algolia
• NEXT_PUBLIC_ALGOLIA_APP_ID=OOK48W9UCL
• NEXT_PUBLIC_ALGOLIA_SEARCH_KEY=ca98597f559459c216891b75989832f8

ALGOLIA_INDEX_PREFIX can be set to a different string until we make sure this works as expected before setting it to sentry-

Closes #9869
Closes #9876
Closes #9778
Closes #6978