Update readme compiler list.

Author: HunterBelanger

README.md

@@ -18,8 +18,8 @@ license.
 ## Dependencies
 The library may be built on Unix-like operating systems or on Windows. All that
 is required is cmake >= 3.11, and a C++ compiler which supports the C++20
-standard. For Unix-like systems, the recommended compilers are GCC >= 11.
-On Windows, you should have MSVC >= 19.29. In order to build the
+standard. For Unix-like systems, the recommended compilers are GCC >= 11 or
+Clang >= 15. On Windows, you should have MSVC >= 19.29. In order to build the
 Python interface, Python >= 3.5 should be installed on your system, in
 addition to the Python development libraries and header files.