Update README.md

[dltmtt]

Update brew syntax

What's this PR do?

• [ ] Add new routes for user
• [ ] Add instruction for using docker-compose

What are the relevant Git tickets?

// Put in link to Git Issue

Screenshots (if appropriate)

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Any background context you want to provide? (if appropriate)

• Is there a blog post?
• Does the knowledge base need an update?
• Does this add new dependencies which need to be added to?

[james-s-w-clark]

I was going to raise PR for this. The code change is correct, this is what's needed to install with brew now.

[ryanjadhav]

+1 can we merge this