docs: fix view_cells.rst

[kenjis]

Description

• improve sample code
• fix minor incorrect descriptions

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• User guide updated
• [] Conforms to style guide

[michalsn]

I have some requests for changes. Some are unrelated to the changes you made here, but since you're polishing the user guide, I thought you would be okay with making them.

[michalsn]

Thanks.