#1362 Docs: Add App about screen docs

doc/helgobox/modules/ROOT/pages/app/user-interface/about-dialog.adoc

@@ -0,0 +1,9 @@
+= About dialog
+
+This dialog appears when you click the xref:app/user-interface/help-menu.adoc#title-bar-about[] button in the help menu.
+
+image::generated/screenshots/main/about.png[]
+
+The version number displayed here is the version of the xref:app.adoc[], not the one of the controlled xref:plug-in.adoc[]! _App_ and _plug-in_ are often updated together, but that's not always the case. They can evolve independently.
+
+In the future, the app will be available as a standalone app, then this distinction will make more sense.

doc/helgobox/modules/ROOT/pages/app/user-interface/help-menu.adoc

@@ -0,0 +1,13 @@
+= Help menu
+
+This menu appears when clicking the xref:app/user-interface/title-bar.adoc#title-bar-help[] button in the window title bar.
+
+include::partial$generated/menus/help/open-helgobox-reference.adoc[]
+
+include::partial$generated/menus/help/open-helgobox-website.adoc[]
+
+include::partial$generated/menus/help/highlight-screen-areas.adoc[]
+
+include::partial$generated/menus/help/about.adoc[]
+
+See xref:app/user-interface/about-dialog.adoc[].

doc/helgobox/modules/ROOT/pages/app/user-interface/title-bar.adoc

@@ -48,11 +48,7 @@ include::partial$generated/elements/title-bar/pause-arrangement.adoc[]
 
 include::partial$generated/elements/title-bar/help.adoc[]
 
-=== Menu entries
-
-include::partial$generated/menus/help/open-helgobox-reference.adoc[]
-include::partial$generated/menus/help/open-helgobox-website.adoc[]
-include::partial$generated/menus/help/highlight-screen-areas.adoc[]
+See xref:app/user-interface/help-menu.adoc[].
 
 include::partial$generated/elements/title-bar/helgobox-info.adoc[]
 

doc/helgobox/modules/ROOT/partials/generated/menus/help/about.adoc

@@ -0,0 +1,8 @@
+ifdef::pdf-theme[[[title-bar-about,About...]]]
+ifndef::pdf-theme[[[title-bar-about,About...]]]
+== About...
+
+
+
+Shows the about screen for the Helgobox App.
+