rabbitmq-diagnostics: add page

[pete-may]

If you are a new contributor to the project, do not use AI to generate pages. We will close any PR with a suspicion of AI usage.

• The page(s) are in the correct platform directories: common, linux, osx, windows, sunos, android, etc.
• The page description(s) have links to documentation or a homepage.
• The page(s) follow the content guidelines.
• The page(s) follow the style guide.
• The PR contains at most 5 new pages.
• The PR title conforms to the recommended templates.
• Version of the command being documented (if known):

Issue: #15705

[Managor]

Suggested change

	- Print the last N log lines on the target node:
	- Print the last `n` log lines on the target node:

[Managor]

Suggested change

	`rabbitmq-diagnostics log_tail --number {{N}}`
	`rabbitmq-diagnostics log_tail --number {{n}}`