docs: add documentation for all commands

[SethFalco]

Documentation for SVGO. The goal is to have svg/svgo.dev pull this documentation to display on a website. The documentation is maintained in MDX, which is Markdown with React components.

Some improvements we can consider for future:

• We have the benefits of reordering nodes/attributes documented twice. We should centralize that information and refer to it.
• Add more documentation in general.
  • Separately document the CLI, JS API, and browser API.
  • Clarify how to use externally maintained plugins.
  • Expand documentation on existing plugins.

Credit

Special thanks to:

• vanillajonathan for asking great questions in Documentation with explanation and motivation #1460.
• GreLI for answering those questions.
• To the contributors who included comments in their plugins.

Related

• Documentation displayed in init: initial website svgo.dev#1
• Closes Insufficient documentation for removeUselessStrokeAndFill #727
• Closes Documentation with explanation and motivation #1460
• Closes Improve docs for convertColors #1464
• Closes Documentation: How to disable a plugin #1760

[vanillajonathan]

Is this documentation built and published anywhere?

[SethFalco]

@vanillajonathan

It's hosted on: https://svgo.dev/