Update generate.md

[corey-at-protenus]

3 changes:

1. note that installing via coursier may be needed.
2. correct link to "your first Scala program"
3. Include the current options for search engines and lazy developers

Can split into multiple if requested. That third change might be contentious :)

[julienrf]

Thank you! Indeed I am not sure about the third point, which might be hard to keep up to date. Also, there are specific pages for the scaladoc tool in Scala 3, which has a page listing the available options: https://docs.scala-lang.org/scala3/guides/scaladoc/settings.html.

I suggest removing the current options of scaladoc from this PR, and opening separate PRs to:

• cross-reference the scaladoc documentation for Scala 2 from the scaladoc documentation for Scala 3 (and vice versa)
• update the list of options of the Scala 3 version

[corey-at-protenus]

@julienrf thanks for your patience. I've updated this PR according to your feedback :)