docs: Add logo. Group external links #65

Job	Run time
docker (prometheus, observability/prometheus, observability/prometheus/Dockerfile.prometheus, cog...	22s
Test observability Quickstart scripts	24s
docker (blackbox, observability/prometheus, observability/prometheus/Dockerfile.blackbox, cogstac...	20s
docker (traefik, observability/traefik, observability/traefik/Dockerfile, cogstacksystems/cogstac...	20s
docker (alloy, observability/grafana-alloy, observability/grafana-alloy/Dockerfile, cogstacksyste...	20s
docker (grafana, observability/grafana, observability/grafana/Dockerfile, cogstacksystems/cogstac...	19s
	2m 5s

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