macro Operator docs

[JV0812]

Purpose of this pull request

This pull request is to create documentation for our new macro 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)

Create documentation for Macro Operator

[kimsauce]

This looks awesome, JV!! Look forward to learning more about this new operator. Just had a few suggestions.

[charlessumo]

Reviewed, I think @manashar4 should take a look here too

[jpipkin1]

@JV0812, shouldn't there be a release note for this feature? It's a big one.

Also, this functionality seems buried by placing it under the Search Operators reference. Shouldn't you place most of the instructions about how to create macros in a new more visible article under "Search Basics"?

[JV0812]

@jpipkin1 Thanks for your suggestions.

• Mostly, this docs will be a Beta release, if confirmed for Beta release I will remove the doc from the sidebar or I will create the release note for the same.
• Let me have a discussion with the Engineering team and confirm on the placeholder. I guess we can keep all these information in the same doc for a Beta release, later we can split it up as you suggested for a common release.