Add additional metadata to GitHub repos

[jerboa88]

We can use fake markdown references to store additional metadata in the README without showing it normally like so:

[meta:exposition]: # (My personal/portfolio site. Made by hand using Gatsby, React, and Tailwind CSS, this static site fetches repository data from the GitHub GraphQL API to display a selection of my public repositories on the home page. This project was a great opportunity to learn more about TypeScript, React, and the GraphQL Data Layer.)
[meta:category]: # (Website)
[meta:technologies]: # (Gatsby, React, Tailwind CSS, daisyUI)
[meta:tools]: # (Git, GitHub, Linux)
[meta:topics]: # (OOP)
[meta:schema:type]: # (WebSite)
[meta:schema:applicationCategory]: # (Website)
[meta:schema:operatingSystem]: # (All)

• In the README of every GitHub repo:
  • Add this metadata
  • Update the URL of the project category badge to the new one hosted on https://johng.io
  • Remove the old data-exposition attribute
• Update the default README template