Speed up contributors onboarding

[zainfathoni]

Overview

Update README.md & CONTRIBUTING.md files with more detailed instructions make onboarding our contributors easier.
The CONTRIBUTING.md document will be used for the kawalcovid19/silacak project as well.

Current Tasks

These are the aspects that we need to cover to ease onboarding our contributors.

Update CONTRIBUTING.md file

• Explain how we utilise Draft Pull Requests to communicate each other (with screenshots) #100
• Explain how to utilise the Labels effectively #102
• Explain how to find new issues to contribute #105
• Explain why we're using English in GitHub Issues & PRs #108
• Add a guide for beginners to look for good first issue label #235
• Separate the CONTRIBUTING.md file based on ID and EN translation #319
• Explain what the Kanban Board and the Prioritization projects mean #101
• Explain what our Milestones for the next few months #103
• Add guide for contributors related to fork repository mechanism #318
• Add documentation about Husky, commitlint #644
• Credential to Netlify CMS and Cloudinary Dashboard #696
• Update CONTRIBUTING.md to educate about disable forked repo actions #736
• Explain our use of Conventional Commits in CONTRIBUTING.md #744
• Document how to add and work with images #569
• Document how to work with Netlify CMS #639

Update README.md file

• Add more principles related to iterative and incremental changes #204
• Document our testing guidelines #731