feat(cli): add support for local templates

[icholy]

Related issue

Fixes #3656

Description

Allow passing local directory as --template parameter.

Checklist

• [x] I have updated the PR title to match CDKTF's style guide
• [x] I have run the linter on my code locally
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation if applicable
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works if applicable
• [ ] New and existing unit tests pass locally with my changes

[icholy]

I'm following the instructions, but I cannot get any of these integration tests to pass locally. It seems to be starting the verdaccio server, but then it errors out when trying to publish with:

npm ERR! code ENEEDAUTH
npm ERR! need auth This command requires you to be logged in to https://registry.yarnpkg.com
npm ERR! need auth You need to authorize this machine using `npm adduser`

How do I setup credentials for this local registry?

[icholy]

Updated.