Added CI.

You need to create a Github action secret NPM_PUBLISH_TOKEN containing the token from npm.

1. Goto npmjs.com and login
2. click on profile picture and Access Tokens
3. Click "Generate new Token" -> "Granular Access Token"
4. Enter a name and set Expiration
5. Under Packages & Scopes select "Read and Write", "Only select packages and scopes", select "@txikijs/types"

6. Click Generate Token & Copy it to github