Update cni-and-neutron.rst

[llokr1]

Description

Expand the CNI and Neutron coexistence documentation

Type of change

• 📝 Documentation content (new or edited pages)
• 🌐 Translation / i18n (localization)
• 🐛 Fix (typo, broken link, build error, wrong information)
• 🔧 Tooling / CI / repository structure
• Other:

Related issue

Fixes #20

Checklist

• I read the Contributing Guide.
• The documentation builds locally: tox -e docs
• The rST sources pass lint: tox -e pep8
• New pages are registered in the parent index.rst toctree.
• rST conventions are followed (one sentence per line, line length < 79,
  heading levels, 한글(English) on first use of a term).

Additional notes

The quotation at line 318 uses the rST .. pull-quote:: directive, but it is not rendered with a distinct visual style.

Is there a project-preferred way to apply block-quote styling?

[llokr1]

I made the changes as follows: @WAFriend3416

[ianychoi]

Looks good thank you