[do not merge] Clack POC

[sarahetter]

Related to: CT-101 (design system) and CT-102 (removing bloat)

This is a POC of using @clack/prompts instead of inquirer for our prompting package.

Reasons we'd like to do this:

• Inquirer (and inquirer-autocomplete-prompt) brings in rxjs which is a huge sub dependency, and we'd like to remove it. (Ends up being around 17MB on filesystem)

• Clack is more customizable than inquirer

Description of clack

Clack has two packages - @clack/core and @clack/prompts.

@clack/core is a group of plain, unstyled prompts. When instantiating a new prompt, you pass a render callback in, and it is updated along with the state when it changes. You can see an example of using @clack/core in src/commands/clack/clack-core.mjs or by running `./bin/run.mjs clack:core.

Prompts is just a pre-styled use of @clack/core with (imo) a pleasant to use interface, and could save us a lot of design and dev time. It also contains some non-prompt utilities such as logging methods to match with the prompts. You can see an example of using @clack/prompts in src/commands/clack/clack-prompts.mjs, or by running ./bin/run.mjs clack:prompts

Screenshots / Gifs

I've converted one command netlify sites:create-template over to @clack/prompts from inquirer

Inquirer (before)	@clack/prompts (after)

[github-actions]

📊 Benchmark results

Comparing with 7dd41c4

• Dependency count: 1,399 ⬆️ 0.29% increase vs. 7dd41c4
• Package size: 404 MB ⬆️ 0.06% increase vs. 7dd41c4

[samkap]

Paired with Sarah today. Small pieces of feedback:

• Change dim to white on input lines (is that what they're called?)
• Switch Success and step green to cyan by default to nod to Netlify branding.