Collector "Deployment" Rewrite

[svrnm]

Copying from #1368 (comment)

A potential structure:

• Calling out once again the flexibility of the collector and linking back to some basic pages (collector concepts, OTLP, ...).
• Maybe some "basics"/"theory" on deployment (collectors can be chained, there can be LBs and other things between you and the collector, using operators etc for rolling them out)
• "0-collector" deployment, go a little bit more into details when you can use no collector, what advantages you have with that model and when you should consider having a collector. It would be the advanced version of what we have discussed a while back on "why otel collector" with @cartermp.
• agent mode collector
• gateway collector
• ...

For the "..." I was thinking about the work @jpkrohling was doing with his talk on deployment models (This is my go to material when people ask me):

https://www.youtube.com/watch?v=WhRrwSHDBFs
https://github.com/jpkrohling/opentelemetry-collector-deployment-patterns/)

from #1368 (comment)

• The Deployment modes page needs some rewording: we don't use the term "Gateway" anywhere else and I think it causes more confusion than clarification.
• There's no different binary nor difference in the configuration between the modes, so it may confuse users. We should either clarify that or remove the notion of "deployment modes" altogether. Perhaps the earlier suggestion on expanding the page to have "patterns" instead would be a good replacement.

[svrnm]

fixed via #2498