Update yarn installation guide

[tobySolutions]

The documentation has "yarn create million@latest" instead of "yarn add million@latest" for the installation guide with yarn

Please describe the changes this PR makes and why it should be merged:

Status

• Code changes have been tested against prettier, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating

Semantic versioning classification:

• This PR changes the codebase
  • This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
  • This PR changes the internal workings with no modifications to the external API (bug fixes, performance improvements)
• This PR only includes non-code changes, like changes to documentation, README, etc.

[vercel]

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Name	Status	Preview	Comments	Updated (UTC)
million-kitchen-sink	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 25, 2023 5:54pm
sink	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 25, 2023 5:54pm

[coveralls]

Pull Request Test Coverage Report for Build 6644227159

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 25.706%

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Totals
Change from base Build 6643984751:	0.0%
Covered Lines:	1257
Relevant Lines:	5082

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💛 - Coveralls