docs: changed emphasis of provider register disclaimer

Addresses a linting issue discovered in the docs.

https://github.com/open-feature/openfeature.dev/actions/runs/7562514753/job/20593130444?pr=359

Signed-off-by: Michael Beemer <[email protected]>

Author: beeme1mr

README.md

@@ -92,7 +92,7 @@ Once you've added a provider as a dependency, it can be registered with OpenFeat
 OpenFeatureAPI.setProviderAndWait(MyProvider())
 ```
 
-_(Asynchronous API that doesn't wait is also available)_
+> Asynchronous API that doesn't wait is also available
 
 
 ### Targeting