docs: in-depth `binarySource` + `install-tool` docs

[jamietanna]

• What's binarySource=global?
• What's binarySource=install?
• How do I install-tool in each way?
• What are the benefits/drawbacks of each?
• What's Containerbase?
• Add a note to feat!: remove binarySource=docker #40747
• Where do the tools get installed from?
• Is there any external connectivity required for tools?
• How do I source tools from i.e. Artifactory?
• What does it look like to build my own Docker container (https://github.com/containerbase/base/blob/main/docs/custom-base-image.md)
• What tools are supported?
  • See also: Use Containerbase's known Tools as a strong type #41849