Update templates for new app

[fasmat]

Now for a fully updated gobuffalo cli. This is the last PR to be merged, after everything else is done.

PRs that need to be merged first (in that order):

• Migrate from packr to fs pop#667
• Replace packr with embed fs buffalo#2166
• Update dependencies for suite suite#46
• Upgrade pop dependency buffalo-pop#29
• Fix broken dependencies mw-i18n#13
• Fix broken dependency to pop fizz#109

[sio4]

PR that needs to be merged before this:

• upgraded to use meta/v2, removed packr, and updated modules clara#7

Anytime before cli. (It is only referenced by cli for now)

[fasmat]

Imho this PR is now ready to be merged. Next steps for the release:

• upgrade to meta/v2 as suggested by @sio4
• only support multi-stage dockerfiles from now on: task: moving docker to be only multi #51
• Add fixers for:
  • Dockerfile
  • suite initialization
  • buffalo.New initialization (= update buffalo.Options fields)
  • buffalo.App.Serve migration from packr to io.FS