GTK 4 tutorial for beginners
v0.85
Toshio Sekiya
Update section 26-30.
Update gfm files of the section 16-30.
Refactor the Rakefile.
Update Rakefile.
Store html files into "docs" directory so that the github page works.
Update section 1-16. Some bugs are fixed.
Bug fixed.
Bug fixed. Readme_for_developers.src.md is Updated.
Update Readme_for_developers.