Improve guix declaration

guix.scm

@@ -4,19 +4,16 @@
              (guix licenses)
              (guix packages))
 
-(let
-  ((%source-dir (dirname (current-filename))))
+(let ((%source-dir (dirname (current-filename))))
   (package
     (name "sjw-wtk")
     (version "devel")
-    (source
-    (local-file %source-dir
+    (source (local-file %source-dir
                         #:recursive? #t
                         #:select? (git-predicate %source-dir)))
     (build-system copy-build-system)
     (arguments
-      '(#:install-plan
-        '(("src" "lib/SJW/WTK"))))
+     '(#:install-plan '(("src" "lib/SJW/WTK"))))
     (home-page "https://git.marvid.fr/Tissevert/WTK")
     (synopsis "The Web Tool Kit")
     (description