Readme - how to update tsconfig for vitest matchers extension

[mibcadet]

What:

Readme was missing info how to update tsconfig for vitest users so extended matchers are not workin in runtime only but also on type checks in devs IDE

Why:

To help devs using typescript and vitest to have typed matchers

How:

After finding solution I edited readme

Checklist:

• Documentation
• Tests N/A
• Updated Type Definitions N/A
• Ready to be merged
  

[mibcadet]

after long studying and trying to solve my problem with missing types for matchers, I investigated threads here #439 and proposed above update as something that could save me a lot of time.

[lortimer]

I ran into this today, what lucky timing! This was very helpful to me - I had all the right imports but my IDE (Webstorm) didn't recognize the jest-dom matchers/extended expect until I added the types to my typescript config.

[gnapse]

@all-contributors please add @mibcadet for docs

[allcontributors]

@gnapse

I've put up a pull request to add @mibcadet! 🎉