Remove all references to `rkt` in documentation

[linghengqian]

• https://github.com/rkt/rkt has been archived since Feb 25, 2020, and has been out of development for years. I think it's inappropriate that documents like https://etcd.io/docs/v3.5/op-guide/container/ still refer to rkt.

rkt Running a single node etcd The following rkt run command will expose the etcd client API on port 2379 and expose the peer API on port 2380.

• I think it's enough for us to just keep the documentation for the Docker part.
• Or we can also add additional documentation for Docker Compose. Projects like https://github.com/etcd-io/jetcd like to use 0.0.0.0 as the ip, which is hardly mentioned in the current documentation. This leads to misunderstandings like https://github.com/apache/shardingsphere/issues/33565 .

  services:
  etcd-test:
  image: gcr.io/etcd-development/etcd:v3.5.10
  command: [ "etcd", "--name", "etcd0", "--advertise-client-urls", "http://0.0.0.0:2379", "--listen-client-urls", "http://0.0.0.0:2379", "--data-dir", "/tmp/etcd-data" ]
  environment:
    ETCD_LOG_LEVEL: info
    ETCD_LOGGER: zap
  expose:
    - 2379
    - 2380

[jmhbnz]

Hey @linghengqian - I completely agree with you on removing the rkt section in all supported versions:

• https://etcd.io/docs/v3.4/op-guide/container/
• https://etcd.io/docs/v3.5/op-guide/container/
• https://etcd.io/docs/v3.6/op-guide/container/

If you have time to assist with this please feel free to raise a pull request, thanks! 🙏🏻

[samuelbartels20]

Hey @linghengqian - I completely agree with you on removing the rkt section in all supported versions:

• https://etcd.io/docs/v3.4/op-guide/container/
• https://etcd.io/docs/v3.5/op-guide/container/
• https://etcd.io/docs/v3.6/op-guide/container/

If you have time to assist with this please feel free to raise a pull request, thanks! 🙏🏻

@jmhbnz Please assign me, i will work them.

[linghengqian]

Hey @linghengqian - I completely agree with you on removing the rkt section in all supported versions:

• https://etcd.io/docs/v3.4/op-guide/container/
• https://etcd.io/docs/v3.5/op-guide/container/
• https://etcd.io/docs/v3.6/op-guide/container/

If you have time to assist with this please feel free to raise a pull request, thanks! 🙏🏻

I personally haven't had time to submit PRs lately. @samuelbartels20 is a better friend to handle the current issue.

[samuelbartels20]

Hey @linghengqian - I completely agree with you on removing the rkt section in all supported versions:

• https://etcd.io/docs/v3.4/op-guide/container/
• https://etcd.io/docs/v3.5/op-guide/container/
• https://etcd.io/docs/v3.6/op-guide/container/

If you have time to assist with this please feel free to raise a pull request, thanks! 🙏🏻

@jmhbnz Please i have raised a PR for this issue

[jmhbnz]

/assign @samuelbartels20

[linghengqian]

• Fixed by https://github.com/etcd-io/website/pull/915 ?