move git config options to top-level in default config

pkg/config/app_config.go

@@ -245,11 +245,11 @@ func GetDefaultConfig() []byte {
       - blue
   commitLength:
     show: true
-  git:
-    merging:
-      manualCommit: false
-    skipHookPrefix: 'WIP'
-    autoFetch: true
+git:
+  merging:
+    manualCommit: false
+  skipHookPrefix: 'WIP'
+  autoFetch: true
 update:
   method: prompt # can be: prompt | background | never
   days: 14 # how often a update is checked for