Document all flags associated with manager

[atoulme]

Component(s)

auto-instrumentation

Is your feature request related to a problem? Please describe.

The manager executable seems to accept a number of ways of configuration:

• A JSON file
• CLI flags
• Env vars

There is no uniformity between those arguments - some env vars for example like ENABLE_WEBHOOKS have no equivalent CLI flag.

Describe the solution you'd like

• Create a documentation for the existing
• Create tests to uniformly enforce how the config is set so each key is sure to have an equivalent in JSON/CLI Flag/Env var
• Fix inconsistencies

Describe alternatives you've considered

No response

Additional context

No response