treewide: remove periods from end of package descriptions

pkgs/applications/audio/picoloop/default.nix

@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
     SDL2_image
     SDL2_ttf
     alsaLib
-    libjack2 
+    libjack2
   ];
 
   sourceRoot = "source/picoloop";
@@ -42,7 +42,7 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with stdenv.lib; {
-    description = "Picoloop is a synth and a stepsequencer (a clone of the famous nanoloop).";
+    description = "Picoloop is a synth and a stepsequencer (a clone of the famous nanoloop)";
     homepage = "https://github.com/yoyz/picoloop";
     platforms = platforms.linux;
     license = licenses.bsd3;