Update doubleslash_style.theme to include external gen2 styling file

- Removed redundant skin parameters and replaced them with a single include statement for doubleslash-gen2.puml to enhance theme consistency.

Author: fknierim

doubleslash_style.theme

@@ -1,61 +1 @@
-skinparam NoteBackgroundColor #D7E9F4
-skinparam NoteBorderColor #D7E9F4
-skinparam backgroundStyle crosshatch
-
-skinparam stereotypeCBackgroundColor #C6C6C6
-
-skinparam Sequence {
-    ParticipantBorderColor #D7E9F4
-    ParticipantBackgroundColor #D7E9F4
-    LifeLineBorderColor #C6C6C6
-    LifeLineBackgroundColor #C6C6C6
-    ArrowColor black
-    GroupBackgroundColor #C6C6C6
-    ActorBorderColor #00A5E1
-    ActorBackgroundColor #00A5E1
-    ActorBorderThickness 2.5
-    ReferenceHeaderBackgroundColor #C6C6C6
-}
-
-skinparam Activity {
-  StartColor #D7E9F4
-  BarColor #D7E9F4
-  EndColor #C6C6C6
-  BackgroundColor #D7E9F4
-  BackgroundColor #D7E9F4
-  BorderColor #D7E9F4
-  FontName Arial
-}
-
-skinparam Usecase {
-    BackgroundColor #D7E9F4
-    BorderColor #D7E9F4
-    ArrowColor black
-    ActorBorderColor #D7E9F4
-    ActorFontName Arial
-    ActorBackgroundColor #D7E9F4
-}
-
-skinparam class {
-    BackgroundColor #D7E9F4
-    ArrowColor black
-    BorderColor black
-    IconColor black
-}
-
-skinparam Interface {
-  backgroundColor #C6C6C6
-  borderColor #C6C6C6
-}
-
-skinparam Component {
-  FontSize 12
-  FontName Arial
-  BorderColor #D7E9F4
-  BackgroundColor #D7E9F4
-  ArrowFontName Arial
-  ArrowColor black
-  ArrowFontColor black
-}
-
-
+!include https://raw.githubusercontent.com/doubleSlashde/umltheme/main/doubleslash/doubleslash-gen2.puml