fixes staging area dot

img/staging-area.dot

@@ -10,8 +10,8 @@ digraph {
     # untracked -> stage [label = "git add"]
     # stage -> untracked [label = "git unstage"]
 
-    workdir -> stage [label = "git stage file"]
-    stage -> workdir [label = "git unstage file"]
+    workdir:sw -> stage:w [label = "git stage file"]
+    stage:e -> workdir:se [xlabel = "git unstage file"]
 
     # workdir -> discard [label = "git restore"]
     # untracked -> discard [label = "rm"]