gnu: starfighter: Rename package to project-starfighter.

* gnu/packages/games.scm (starfighter): Define in terms of
'deprecated-package'.
(project-starfighter): New variable, formerly known as "starfighter".

gnu/packages/games.scm

@@ -3186,9 +3186,9 @@ tactics.")
                    license:gpl2+
                    license:lgpl2.1+))))
 
-(define-public starfighter
+(define-public project-starfighter
   (package
-    (name "starfighter")
+    (name "project-starfighter")
     (version "1.7")
     (source (origin
               (method url-fetch)
@@ -3221,6 +3221,9 @@ in strikes against the evil corporation.")
                    license:cc0
                    license:public-domain))))
 
+(define-public starfighter
+  (deprecated-package "starfighter" project-starfighter))
+
 (define-public chromium-bsu
   (package
     (name "chromium-bsu")