Some repositories are updated

Some repositories are updated.

The following repositories are updated.

• GTK4 tutorial
• GObject tutorial

GTK4 tutorial

• All the contents have been reviewed and rewritten. Now it covers GTK version 4.10.
• Some bugs are fixed.
• Many programs are modified and improved.
• A new section, drag and drop, is added.

GTK version 4.10 adds some new classes and make some old classes deprecated. For example, GtkFileChooserDialog is replaced by GtkFileDialog. The change was pretty wide so the tutorial has also been changed a lot.

GObject tutorial

• All the contents have been reviewed and rewritten.
• Some bugs are fixed.
• Many programs are modified and improved. For example, TComparable interface programs are changed widely.