Building steps issues

[mateusz-plociennik]

Hi! I attempted to reproduce the build steps using the latest versions today, as of 2 May 2024. I am running the steps on a fresh installation of macOS Ventura 13.5.2 with Homebrew installed. Here are the issues I found:

1. In step 4, you request the feaLib-STAT branch of https://github.com/fonttools/fonttools, which no longer exists. I believe the feature was merged into the main branch, so it is safe to assume we can drop the @feaLib-STAT part of the URL.
2. One of the fonttools dependencies, pycairo, requires pkg-config to be installed. This can be addressed with an additional step: brew install pkg-config on macOS.
3. When running the tools/01_export_fontlab_lato.vfpy script in FontLab-8, I received the following warning: Incorrect user range in axis "weight" (1-1000 required).
4. The current version of fontmake has an API change: the FontProject.run_from_designspace() function argument designspace_path was renamed to designspace.

After that, the font was built successfully, but I am not sure of its correctness.