Suggest CONTRIBUTING.md for each framework

[sykim-etri]

I suggest CONTRIBUTING.md for each framework as follows:
It's from Kubernetes CONTRIBUTING.md

---

Contributing

Welcome to Cloud-Barista <???>! To learn more about contributing to the Cloud-Barista, check out the Contributor's Guide.

The Cloud-Barista homepage contains information about how to get started, how the community organizes, and more.

[jihoon-seo]

How about "website", instead of "homepage"?

https://en.wikipedia.org/wiki/Home_page

A home page (also written as homepage) is the main web page of a website.
A home page is generally the main web page a visitor navigating to a website from a search engine will see

https://www.moreycreative.com/blog/homepage-vs-site-page-vs-landing-page

A homepage is the starting point of a website, which loads when visitors go to the domain name (ex: https://www.moreycreative.com/). Your homepage serves as the entrance to the rest of your site, catching visitors' attention and helping to guide them throughout its various pages.

[jihoon-seo]

[TODO]

• https://github.com/cloud-barista/cb-ladybug
  • README.md 에 "Contribution" 섹션이 있음
• https://github.com/cloud-barista/cb-dragonfly
• https://github.com/cloud-barista/cb-webtool