docs(FamilyRank): 修改导航栏标题为'家庭步数排行榜'

 export default {
 export default {
-  navigationBarTitleText: '活动排行榜',
+  navigationBarTitleText: '家庭步数排行榜',
   usingComponents: {
   usingComponents: {
   },
   },
 }
 }