Adding docs on how to authenticate with prometheus to nifi 2.x.x metrics #2197

Job	Run time
Run Rustfmt	29s
Run Cargo Udeps	1m 53s
Run Cargo Deny (bans licenses sources)	23s
Decide if Helm charts are pushed to the helm repository based on action trigger	2s
Run Cargo Deny (advisories)	22s
Run Clippy	25s
Check if committed README is the one we would render from the available parts	24s
Run RustDoc	1m 9s
Run Cargo Tests	37s
Check if committed Helm charts are up to date	45s
All tests passed	2s
Package Charts, Build Docker Image and publish them - ubicloud-standard-8-arm	11m 54s
Package Charts, Build Docker Image and publish them - ubuntu-latest	17m 42s
Build and publish manifest list	57s
Run the OpenShift Preflight check on the published images	39s
	37m 43s

Provide feedback