Clarify acquire method's signature changed in CHANGELOG.md

[luislobo]

Hi,

Our team detected that there are breaking changes coming from an old version (1.x) to 3.1.0+

The CHANGELOG.md mentions about a breaking change, but it says to replace from FairSemaphore to Semaphore but it doesn't warn that the acquire method no longer returns a boolean, and rather, throws when it cannot acquire, and returns nothing.

I think it would be good to add this into the CHANGELOG.md entry, in case other are coming from an old version (like us).

Thank you!

Luis