about: Change app name to Loupe and update devs

- Rename to Loupe to avoid confusion during incubation
  and potentially allow for release on Flathub
- Replace GNOME as developer since it violates software policy
- Put a more useful copyright statement
- Add me as developer

data/gtk/window.ui

@@ -51,7 +51,7 @@
         <attribute name="action">win.show-help-overlay</attribute>
       </item>
       <item>
-        <attribute name="label" translatable="yes">_About Image Viewer</attribute>
+        <attribute name="label" translatable="yes">_About Loupe</attribute>
         <attribute name="action">app.about</attribute>
       </item>
     </section>
@@ -60,7 +60,7 @@
     <property name="default-width">600</property>
     <property name="default-height">498</property>
     <property name="width-request">360</property>
-    <property name="title" translatable="yes">Image Viewer</property>
+    <property name="title" translatable="yes">Loupe</property>
     <binding name="title">
       <closure type="gchararray" function="window_title">
         <lookup type="LpImageView" name="active-file">image_view</lookup>
@@ -144,7 +144,7 @@
                     <property name="vexpand">True</property>
                     <child>
                       <object class="AdwStatusPage" id="status_page">
-                        <property name="title" translatable="yes">Image Viewer</property>
+                        <property name="title" translatable="yes">Loupe</property>
                         <property name="description" translatable="yes">Click “Open File…” or drag an image here.</property>
                         <child>
                           <object class="GtkButton">