Clarify in the changelog what "preliminary support for Py_LIMITED_API" means.
Clarify in the changelog what "preliminary support for Py_LIMITED_API" means.

Closes https://github.com/cython/cython/issues/4113

scoder/cython,da-woods/cython,da-woods/cython,scoder/cython,scoder/cython,da-woods/cython,cython/cython,scoder/cython,da-woods/cython,cython/cython,cython/cython,cython/cython