CLI Feature: Project scaffolding - Milestone 1

[flyinglimao]

Description

This PR is for issue #31.

We add a new command flow app create. By this command, users can create a flow project based on example scaffold and setup stacks they want to use.

Submission Links & Documents

• PR to Flow-CLI
• Repo for scaffold

Requirements Check

• Have have you met the milestone requirements? yes
• Have you included tests (if applicable)? no
• Have you met the contribution guidelines of the repos you have submitted code to (if applicable)? yes
• If this is the last milestone:
  • Demonstrate that you've met all the acceptance criteria (link to code, demos, instructions to run etc.)
  • Check the PR
  • Demonstrate that you've met all milestone requirements and highlight any extensions or additional work done.
  • Check the PR

Other Details

• Is there anything specific you'd like the PoC to know or review for?
• Are there other references, documentation, or relevant artificats to mention for this PR (ie. external links to justify design decisions, etc.)?

[kerrywei]

summary: suggestions were given in https://github.com/onflow/flow-cli/pull/404, pending applicant to address

[kerrywei]

closing this PR -- Gregor and @flyinglimao are working on tweaking the PR https://github.com/onflow/flow-cli/pull/404 Thank you for participating in the FLIP FEST @flyinglimao !