Update documentation about review mode

[bsekachev]

My actions before raising this issue

• Read/searched the docs
• Searched past issues

Context

If two issue tags created at the same place it was impossible to access on of them (#2607).
To fix the behavior we've added the feature of scrolling these tags by mouse wheel (#2868) as shown on the gif below.
Need to hover cursor under an issue and use wheel your mouse. We should add a piece of information about it to our user guide

[nmanovic]

@TOsmanov , could you please check that it is covered by our documentation? If it is not, please add corresponding information. I will close the issue.