Fix typo in README.md

[LilithHafner]

No description provided.

[anoadragon453]

Hi @LilithHafner, thank you for catching this!

While I know this is a tiny change, we still require all contributors to sign off on their changes.

That basically boils down to adding the following in a github comment or to your git commit:

Signed-off-by: Your Name <[email protected]>

(Real name is required.) Thank you!

[uhoreg]

Thanks!