Adds an extra section to the Legal page.
Extra sections will be displayed below the application's own information.
The parameters copyright, license_type and license will be used to present the it the same way as
[property@AboutDialog:copyright], [property@AboutDialog:license-type] and [property@AboutDialog:license] are for the application's own
information.
See those properties for more details.
This can be useful to attribute the application dependencies or data.
Examples:
```c adap_about_dialog_add_legal_section (ADAP_ABOUT_DIALOG (about), _("Copyright and a known license"), "© 2022 Example", GTK_LICENSE_LGPL_2_1, NULL);
adap_about_dialog_add_legal_section (ADAP_ABOUT_DIALOG (about), _("Copyright and custom license"), "© 2022 Example", GTK_LICENSE_CUSTOM, "Custom license text");
adap_about_dialog_add_legal_section (ADAP_ABOUT_DIALOG (about), _("Copyright only"), "© 2022 Example", GTK_LICENSE_UNKNOWN, NULL);
adap_about_dialog_add_legal_section (ADAP_ABOUT_DIALOG (about), _("Custom license only"), NULL, GTK_LICENSE_CUSTOM, "Something completely custom here."); ```
| this |
an about dialog |
| title |
the name of the section |
| copyright |
a copyright string |
| license_type |
the type of license |
| license |
custom license information |