VS Code, autocomplete feature, add a 50,000 word dictionary

Greetings to this community of geniuses! (That helped me out so often)

New to Vscode and with a modest level in programming, I'm trying to have my own list of words (plain text) come up in that drop-down menu that unfolds as you type.

Also it would be useful if it triggered only from the third letter of the word i type, but that's another question.

I tried all sorts of keywords to find similar concerns and answers but in vain.

Another endeavor, but more complex, I'd like to have, in a subtitle timing file, the number/separator patterns automatically checked, as well as basic check for the interspersed text (capitalization, etc.).

Any hint or guidance welcome, even just keywords to google would be appreciated.

Thank you for your help. Éric http://paroissien-linguists.com