Add information about the field= operator

[JV0812]

Purpose of this pull request

This pull request is to add the difference between using the field and field= operator.

Select the type of change

• Minor Changes - Typos, formatting, slight revisions
• Update Content - Revisions, updating sections
• New Content - New features, sections, pages, tutorials
• Site and Tools - .clabot, version updates, maintenance, dependencies, new packages for the site (Docusaurus, Gatsby, React, etc.)

Ticket (if applicable)

Update documentation with difference between fields and fields = operator syntax