[Doc] add docs for "how to develop plugin" in "development" guide

[Anonymitaet]

Need to add docs for the following missing contents on https://pulsar.apache.org/docs/next/developers-landing/

Related code PR: #12536

[momo-jun]

Status update: Pending.
Confirmed with @codelipenghui today.

[github-actions]

The issue had no activity for 30 days, mark with Stale label.

[momo-jun]

Hi @codelipenghui, any updates or plan for this doc?

[momo-jun]

@codelipenghui
Does this new doc-required PR #14729 have dependency on this issue?

[github-actions]

The issue had no activity for 30 days, mark with Stale label.

[github-actions]

The issue had no activity for 30 days, mark with Stale label.

[tisonkun]

Closed as stale and no interest. This can be part of #18272 when we later touch it.