fish: added some git aliases

shells/fish/functions/g.fish

@@ -1,3 +1,27 @@
 function g
-    git $argv
+        git $argv
+end
+
+function gst
+        git status $argv
+end
+
+function gcom
+        git commit $argv
+end
+
+function gad
+        git add $argv
+end
+
+function gup
+        git push $argv
+end
+
+function gdo
+        git pull $argv
+end
+
+function gdif
+        git diff $argv
 end