Update readme to include references to ghcr.io/lightstep/otel-collector-charts/otelcolarrow-experimental

[tratnayake]

Description

• Update readme with references to the otelcolarrow-example prebuilt docker image on GHCR.
• Note packages can be examined here: https://github.com/orgs/lightstep/packages?tab=packages&q=otel
  • i.e. this specific one: https://github.com/orgs/lightstep/packages?tab=packages&q=otel

How Has This Been Tested?

• GHA workflow runs as expected: https://github.com/lightstep/otel-collector-charts/actions/runs/7024362460
• Confirmed able to pull the docker image

  docker pull ghcr.io/lightstep/otel-collector-charts/otelarrowcol-experimental:latest
  latest: Pulling from lightstep/otel-collector-charts/otelarrowcol-experimental
  96526aa774ef: Pull complete
  58f05ea3c670: Pull complete
  Digest: sha256:66f2ec4ddf9b9d2e196f3bf89d1fadf38c0ce4b5008e1929964cbd00ed81ab1d
  Status: Downloaded newer image for ghcr.io/lightstep/otel-collector-charts/otelarrowcol-experimental:latest
  ghcr.io/lightstep/otel-collector-charts/otelarrowcol-experimental:latest

• Confirmed able to run the docker image

❯ ls                                                                                           15:20:30
LICENSE            arrow              ct.yaml
README.md          charts             gateway-build.yaml
❯ cd arrow                                                                                     15:20:31
❯ ls                                                                                     15:20:32
Dockerfile              Makefile                config                  otelcolarrow-build.yaml
❯ docker run -it -v ./config/:/config --entrypoint /otelarrowcol ghcr.io/lightstep/otel-collector-charts/otelarrowcol-experimental:latest --config=/config/saas-collector.yaml
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
2023-11-28T23:21:12.925Z    info    service@v0.89.0/telemetry.go:85 Setting up own telemetry...
2023-11-28T23:21:12.935Z    info    service@v0.89.0/telemetry.go:202    Serving Prometheus metrics  {"address": "127.0.0.1:8889", "level": "Normal"}
2023-11-28T23:21:12.937Z    warn    headerssetterextension@v0.88.0/extension.go:55  The action was not provided, using 'upsert'. In future versions, we'll require this to be explicitly set    {"kind": "extension", "name": "headers_setter"}
2023-11-28T23:21:12.952Z    info    exporter@v0.89.0/exporter.go:275    Development component. May change in the future.    {"kind": "exporter", "data_type": "traces", "name": "debug"}
2023-11-28T23:21:12.955Z    info    exporter@v0.89.0/exporter.go:275    Development component. May change in the future.    {"kind": "exporter", "data_type": "metrics", "name": "debug"}
2023-11-28T23:21:12.963Z    info    service@v0.89.0/service.go:143  Starting otelarrowcol...    {"Version": "0.10.0", "NumCPU": 5}
2023-11-28T23:21:12.963Z    info    extensions/extensions.go:34 Starting extensions...
2023-11-28T23:21:12.963Z    info    extensions/extensions.go:37 Extension is starting...    {"kind": "extension", "name": "headers_setter"}
2023-11-28T23:21:12.964Z    info    extensions/extensions.go:45 Extension started.  {"kind": "extension", "name": "headers_setter"}
2023-11-28T23:21:12.970Z    info    otelarrowreceiver@v0.10.0/otlp.go:98    Starting GRPC server    {"kind": "receiver", "name": "otelarrow", "data_type": "traces", "endpoint": "127.0.0.1:8100"}
2023-11-28T23:21:12.972Z    info    service@v0.89.0/service.go:169  Everything is ready. Begin running and processing data.
^C2023-11-28T23:21:20.810Z  info    otelcol@v0.89.0/collector.go:258    Received signal from OS{"signal": "interrupt"}
2023-11-28T23:21:20.811Z    info    service@v0.89.0/service.go:178  Starting shutdown...
2023-11-28T23:21:20.831Z    info    extensions/extensions.go:52 Stopping extensions...
2023-11-28T23:21:20.832Z    info    service@v0.89.0/service.go:192  Shutdown complete.

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R/CC: Who should know about this change? Requesting any reviewers in particular?