feat(cli): add support for local templates

[icholy]

Related issue

Fixes #3656

Description

Allow passing local directory as --template parameter.

Checklist

• I have updated the PR title to match CDKTF's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• 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?

[DanielMSchmidt]

Thanks for the help! Could you add the new functionality to the help text as well?

terraform-cdk/packages/cdktf-cli/src/bin/cmds/init.ts

Line 17 in c3174e6

.option("template", {

[icholy]

Updated.