docs: simplify contributing page

[fyliu]

Overview

We need contributing docs more suitable for contributors of our project that should already know the basics. The main page should be kept simple with links to more detailed explanations. A short but useful contributor intro to the project will make it more accessible.

Action Items

• Create a contributing folder in docs/ to hold contributing pages
• Move most or all sections out of the contributing page into pages in contributing/
• Split CONTRIBUTING.md from docs/contributing/index.md
  • Replace links to CONTRIBUTING.md with short description and link to contributing/index.md
  • Replace contributing/index.md sections with short descriptions and links to individual pages

Instructions

• Keep the contributing page short but usable by experienced devs
• Link to detailed pages for clarification
• What this means is to expand the CONTRIBUTING.md file into a folder of contributing documents for everything related to PD development

  contributing
  ├── index.md
  ├── team.md
  ├── dev_environment.md
  ├── issues.md
  ├── git.md
  ├── documentation.md
  ├── ...
  ├── how-to
  │   ├── add-model-and-api-endpoints.md
  │   └── ...
  └── tools
      ├── docker.md
      └── ...
  

[fyliu]

Edited the issue description around the goal of simplifying the page. Removed text that should go into separate issues.

[fyliu]

The complexity is small since it doesn't modify most of the contents of the newly created pages. That will be done in future issues.

[fyliu]

Updated issue tasks to split CONTRIBUTING.md from contributing/index.md. The page used to just be a reference to CONTRIBUTING.md

The problem with this issue is it splits up CONTRIBUTING.md into smaller files, and any other PR changing CONTRIBUTING.md is going to get a massive conflict with it. I see PR #370 having one of those changes, so I will create this issue's PR when that's merged.

[fyliu]

I need to create the PR from my changes. Need an hour's time.

I have the changes done but I was trying to figure out if there's a way to do the commits so it's easier for other people to merge changes from before my changes, because my change splits 1 file into 5-6 files. I tried it and the changes is about 100% of the files.

If I don't figure out a way with the git diff strategies, I'll just create the PR from what I have.

[fyliu]

I created a guide for manually applying changes to a different files, so that if someone made changes to the old long CONTRIBUTING.md, they can manually but successfully apply those changes as patch files when merging. Link

[fyliu]

I reverted some code that removed the 3-column layout, which is not part of this issue, and remade the screenshots. The PR is ready for review again.