Move and consolidate docs

[sa7mon]

The README is really long and can be daunting. Let's keep the readme short to give a quick overview and move all the details to markdown files. Maybe under /docs?

• Detailed usage - moved from readme
• Providers
  • list all supported providers and any weirdness with them
  • which providers support authenticated scans (only AWS for now)
  • how to add a new provider
• Setting up the development environment
• custom config file format
• List of other APIs to test from the wiki
• Permissions - understanding the results
• Nice graphic highlighting the sections of the default output format
• Database diagram

[sa7mon]

Add note to AWS section about rate limits

#325

[sa7mon]

Using Docusaurus. Content outline:

• Installation
• Usage
  • Basic
  • Full
  • Config File
  • Rabbit MQ
• Storage Providers
  • Supported
  • To Test
  • Custom
  • Specific provider notes
    • Forbidden bucket names
• Database
  • Schema
  • Note about overwriting with Gorm
• Developing
  • Setup development environment
  • Contributing a new provider