docs: deprecate the how-compile-my-project guide

[Zodiarche]

Summary

Deprecates the migrated guide how-compile-my-project by 301-redirecting its old URLs to their new home on docs.pokemonworkshop.com and removing the old page (both locales). Part of the incremental documentation migration (refs #7).

Redirects

Locale	Old URL	New URL
EN	https://pokemonworkshop.com/en/help/pokemon-sdk/how-compile-my-project/	https://docs.pokemonworkshop.com/pokemon-studio/create-a-playable-version/
FR	https://pokemonworkshop.com/fr/help/pokemon-sdk/how-compile-my-project/	https://docs.pokemonworkshop.com/fr/pokemon-studio/creer-une-version-jouable/

Changes

• Add EN + FR RewriteRule (R=301,L) in public/.htaccess, in the # 1b. block.
• Delete how-compile-my-project_en.mdoc and how-compile-my-project_fr.mdoc.

Test plan

• bun run build passes (490 pages, index grids regenerate without the removed page).
• New docs targets return HTTP 200 (checked EN + FR with curl).
• Old URLs 301 to the new docs URLs once deployed.

refs #7