Update index.mdx to fix a typo

[jimexist]

Changes

Please describe.

a typo where set_once should be used

Add screenshots or screen recordings for visual / UI-focused changes.

No UI changes are observed, just updating docs

Checklist

• Words are spelled using American English
• Titles are in sentence case
• Feature names are in sentence case too
• Use relative URLs for internal links
• If I moved a page, I added a redirect in vercel.json
• Remove this template if you're not going to fill it out!

Article checklist

• I've added (at least) 3-5 internal links to this new article
• I've added keywords for this page to the rank tracker in Ahrefs
• I've checked the preview build of the article
• The date on the article is today's date
• I've added this to the relevant "Tutorials and guides" docs page (if applicable)

Useful resources

• The PostHog style guide
• Full list of tags and categories
• List of content components
• PostHog SEO best practices

[vercel]

@jimexist is attempting to deploy a commit to the PostHog Team on Vercel.

A member of the Team first needs to authorize it.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated (UTC)
posthog	✅ Ready (Inspect)	Visit Preview	May 23, 2024 8:24pm

[marandaneto]

@PostHog/website-docs can you authorize vercel and merge it, please? thanks.