Migrate `TODOs` list from `README.md` to be tracked by `Issues` instead

[htbkoo]

Copied from README.md as of 30-Oct-2021:

TODOs

7. [ ] Fix issues mentioned in PageSpeed or Lighthouse, e.g.
   1. [x] Issues under PWA section
   2. [ ] (#61) Issues under Performance section
      1. [x] (#67) Reduced First Contentful Paint by adding explicit loading screen and refactored to download font and icon asynchronously
8. [ ] (#68) Improve tests
9. [ ] Refactor code, e.g.
   1. [ ] (#69) Migrate to React Hooks for clarity wherever applicable
   2. [ ] (#70) Review components splitting / architecture wherever applicable
   3. [ ] (#71) Generic code refactoring
10. [ ] Add more section README.md, e.g.
    1. [ ] Quick Overview
    2. [ ] Installation
11. [ ] (#46) Re-architecture, e.g.
    1. [x] Add react-router support
       1. no longer necessary, already supported by Next.js page router
    2. [ ] Try out if micro-frontend is a good fit for this project
12. [ ] (#72) Revamp design, e.g.
    1. [ ] Re-organize components layout, e.g.
       1. [ ] replace Drawer by navbar?
    2. [ ] Add Blog / My learning notes section (#53)
       1. [ ] The contents can be stored as markdown in GitHub repo directly?
    3. [x] Group pages and do not put all of them at the same page?
    4. [x] Add animation
13. [x] Update project license
14. [x] (If applicable) merge the PRs raised by dependabot to fix potential security vulnerabilities
15. [x] (#34) Update project dependencies, which includes:
    1. react + react-dom
    2. typescript
    3. react-scripts
    4. material-ui
    5. cheerio
    6. react-ga
16. [x] Fix the content at anchor hidden by header bar issue, references:
    1. css-tricks
       1. Hash Tag Links That Don’t Headbutt The Browser Window
       2. Fixed Headers, On-Page Links, and Overlapping Content, Oh My!
       3. Link in Header? Or Header in Link?
    2. nicolasgallagher.com
       1. Jump links and viewport positioning
    3. stackoverflow
       1. Fixed page header overlaps in-page anchors
17. [x] Add GitHub action to automatically:
    1. [x] Run tests for all PRs and merges into master
    2. [x] Build docs/ and deploy to gh-pages
18. [x] Add Fork me on GitHub ribbon
    1. Done by adding link to repo at version text

[htbkoo]

Ideas / Thinking aloud

1. [ ] Playground page - try to build games on webpage
   1. [ ] Picross
2. [ ] Experiments page - experiment to learn and use various technologies
   1. [ ] Web Assembly (wasm)
      1. AssemblyScript
      2. c++
      3. python
   2. [ ] AIML (tensorflow.js)
   3. [ ] Displaying Jupyter Notebook on portfolio page
3. [ ] Blog / Learning notes page - study notes #53
   1. System design
   2. Web / frontend
   3. Data Structure and Algorithm
4. [x] Tools page
   1. [x] Link to htbkoo/CssToAndFromReact
      1. not linked, but merged