[doc] Create docs to help user collect pprof info when reporting performance issue

[csantanapr]

Today we discussed this issue argoproj/argo-cd#13534 on high CPU utilization on argocd controller.
The end user wanted to know more information on which go task/function the CPU comsume the most CPU, tracing gave a span on time spent but the span covers two functions handing the watch event and doing the ignore difference.

It would be useful to have docs that show the steps for the end user to use pprof to debug the argocd components and get more insights on what's going on.

[csantanapr]

On Slack an end user Lukas Wöhrl is using pixie https://px.dev/ to do profiling with flame graph to determined which go rutines are the ones taking the longest

I think it would be awesome to document this process and share with end user community when reporting performance issues to use pixie to take a look at argocd controllers