add FAQ entry on Apple-silicon package availability

Author: slayoo

README.md

@@ -210,6 +210,8 @@ flowchart TD
 ```
 
 ## FAQ
+- Q: Why `pip install PyPartMC` triggers compilation on my brand new Apple machine, while it quickly downloads and installs binary packages when executed on older Macs, Windows or Linux?    
+  A: We are not yet providing binary wheels on PyPI for Apple-silicon (arm64) machines. Cross-compilation with gfortran is only supported with experimental unofficial builds [and is tricky](https://github.com/iains/gcc-12-branch/issues/23), while Github Actions ARM64 virtual machines are [costly](https://docs.github.com/en/billing/managing-billing-for-github-actions/about-billing-for-github-actions#minute-multipliers).  
 
 - Q: Why some of the constructors expect data to be passed as **lists of single-entry dictionaries** instead of multi-element dictionaries?    
   A: This is intentional and related with PartMC relying on the order of elements within spec-file input; while Python dictionaries preserve ordering (insertion order), JSON format does not, and we intend to make these data structures safe to be [de]serialized using JSON.