Fix broken link in User Guide

[anubh-v]

What is the purpose of this pull request? (put "X" next to an item, remove the rest)

• [X ] Documentation update
• [X ] Bug fix

Fixes #843
What is the rationale for this request?
To fix a broken link in the user guide.

What changes did you make? (Give an overview)
I replaced a link in userGuide/cliCommands.md.

Provide some example code that this change will affect:
N.A.
Is there anything you'd like reviewers to focus on?
N.A.

Testing instructions:
Manually verify the correctness of the new link using a locally generated copy of the site.

Proposed commit message: (wrap lines at 72 characters)

User Guide: Fix broken link to section on converting an existing wiki

There is a broken link in the explanation of the `init` command,
under the References section of the user guide.

Let's replace this link with the correct link, so information is
communicated effectively to users.

[yamgent]

Hi, thanks for your PR, your current changes looks good. 👍

May I know whether you are planning to add more changes? Am wondering because this PR is in draft mode...

[anubh-v]

Thanks @yamgent
I have nothing else to add, accidentally left this PR as a draft.