improve git pull behaviour

gitconfig

@@ -5,7 +5,7 @@
     ci = commit
     co = checkout
     a = add
-    p = pull --rebase
+    p = pull --ff-only
     s = status -sb
     lv = log --pretty=format:"%C(yellow)%h%Cred%d\\ %Creset%s%Cblue\\ [%cn]" --decorate --numstat
     lg = log --graph --pretty=format:"%C(yellow)%h\\ %ad%Cred%d\\ %Creset%s%Cblue\\ [%cn]" --decorate --date=relative