Rename README_EGL_MSVC.txt to README_FEATURES_MSVC.txt, as we now have
more features that can be included in the builds using the Visual
Studio projects, which require additional depedencies and manual
enabling.
Specifically, this outlines how the font tweaking feature in libgtk can
be enabled and for people who wish to do so, how to enable the Font
Features demo in gtk3-demo.exe.