Proposal to create a welcome app for XFCE

[Айрат Махмутов]

Hello Alexander,

Thank you for your quick and clear answer. I understand now why 
Blueprint is not a good fit for XFCE, and I appreciate you explaining that.

You mentioned using Glade for GUI building. I am concerned that Glade's 
development has slowed down. Instead, I would like to use Cambalache as 
the UI designer tool. It is a modern alternative that supports both GTK3 
and GTK4, which makes it a great fit for XFCE.

Link: https://gitlab.gnome.org/jpu/cambalache

To make sure it works well with XFCE-specific widgets, I have already 
successfully added support for |Libxfce4ui|to Cambalache. I used the 
|gir|file to generate a catalog, and it worked. Here is the catalog file 
it created:

<?xml version='1.0' encoding='UTF-8' standalone='no'?>
<!DOCTYPE cambalache-catalog SYSTEM "cambalache-catalog.dtd">
<cambalache-catalog name="Libxfce4ui" namespace="Libxfce4ui" prefix="Xfce" version="2.0" targets="2.0,4.16,4.18,4.19">
   <type>
         ("XfceClipboardManager","GObject","Libxfce4ui","4.19.5",None,None,1,None,None,None),
         ("XfceFilenameInput","GObject","Libxfce4ui",None,None,None,1,"container",None,None),
         ("XfceSMClient","GObject","Libxfce4ui",None,None,None,None,None,None,None),
         ("XfceScreensaver","GObject","Libxfce4ui","4.18.2",None,None,1,None,None,None),
         ("XfceTitledDialog","GObject","Libxfce4ui",None,None,None,1,"container",None,None)
   </type>
... [rest of the XML content] ...
</cambalache-catalog>

I am committed to developing and maintaining this welcome application. I 
can promise to maintain it for the long term, at least until 2027.

This will be my first GTK application, so I would be very grateful if 
someone from the team would be willing to review my code and provide 
guidance.

Thank you for your consideration and for asking others on Matrix.

Best regards,
Ajrat Makhmutov