Integrate tarantool.io/en/dev/core & internals

Epic: Restructure Tarantool docs, stage 3

SME: @ kyukhin

Details

• Here is the documentation to Tarantool internals that are relevant mostly for Tarantool developers: https://github.com/tarantool/tarantool-internals.
• Here is other internals documentation useful for other developers (like connector developers): https://www.tarantool.io/en/doc/latest/dev_guide/internals/
• Make sure the readers can find both sources.
• Due to limited team capacities, there are currently no resources to create a unified search engine for /doc, /enterprise_doc, and /dev/core. Moreover, Sphinx has issues with external links in the menu.
• We can still help devs find the information by creating a workaround. We can write an introductory page for internals with all the keywords in /doc and provide links to /dev/core. This page will also link to the existing internals hosted at /doc.

Definition of done

• Add meaningful overview text to the Internals page, linking to all the important sections in /dev/core and /dev_guide/internals
• Redirect if needed

Related tasks (JFYI)

• https://github.com/tarantool/doc/issues/1657
• https://github.com/tarantool/doc/issues/3164

@ veod32 says:
"Как мне кажется, сейчас Internals — это какая-то сборная солянка, утратившая актуальность"

Start by reviewing the existing Internals page and the linked tarantool-internals and /dev_guide/internals documentation to identify the important sections and current links. Check whether a redirect is needed, then update the Internals page with an overview linking to both sources. Done means readers can find the relevant internals information from that page.