Add tutorial for standalone agent on serverless monitoring nginx#906

Merged

kilfoyle merged 5 commits intoelastic:mainfrom kilfoyle:904/nginx-serverless

Feb 13, 2024

+362-40

Commits on Feb 8, 2024

Commits on Feb 12, 2024

Change original guide to use API key auth
kilfoyle
committed

Commits on Feb 13, 2024

Change IDs to -ess; small fixes
kilfoyle
committed