add Chinese translation to all levels in 'Ramping up','Advanced Topics' and modify the other levels's translation except those in 'A Mixed Bag'.

src/levels/rampup/relativeRefs2.js

@@ -3,10 +3,12 @@ exports.level = {
   "solutionCommand": "git branch -f master C6;git checkout HEAD~1;git branch -f bugFix HEAD~1",
   "startTree": "{\"branches\":{\"master\":{\"target\":\"C4\",\"id\":\"master\"},\"bugFix\":{\"target\":\"C5\",\"id\":\"bugFix\"}},\"commits\":{\"C0\":{\"parents\":[],\"id\":\"C0\",\"rootCommit\":true},\"C1\":{\"parents\":[\"C0\"],\"id\":\"C1\"},\"C2\":{\"parents\":[\"C1\"],\"id\":\"C2\"},\"C3\":{\"parents\":[\"C1\"],\"id\":\"C3\"},\"C4\":{\"parents\":[\"C2\"],\"id\":\"C4\"},\"C5\":{\"parents\":[\"C3\"],\"id\":\"C5\"},\"C6\":{\"parents\":[\"C5\"],\"id\":\"C6\"}},\"HEAD\":{\"target\":\"C2\",\"id\":\"HEAD\"}}",
   "hint": {
-    "en_US": "You'll need to use at least one direct reference (hash) to complete this level"
+    "en_US": "You'll need to use at least one direct reference (hash) to complete this level",
+    "zh_CN": "这一关至少要用到一次直接引用(hash)"
   },
   "name": {
-    "en_US": "Relative Refs #2 (~)"
+    "en_US": "Relative Refs #2 (~)",
+    "zh_CN": "相对引用2(~)"
   },
   "startDialog": {
     "en_US": {
@@ -62,6 +64,60 @@ exports.level = {
           }
         }
       ]
+    },
+    "zh_CN": {
+      "childViews": [
+        {
+          "type": "ModalAlert",
+          "options": {
+            "markdowns": [
+              "### The \"~\" operator",
+              "",
+              "假设需要在提交树中向上移动很多步。使用多个`^`非常无聊，所以Git也引入了波浪(~)操作符。",
+              "",
+              "",
+              "波浪操作符后面可以（可选地）跟一个数字，指定向上移动多少次。看个例子"
+            ]
+          }
+        },
+        {
+          "type": "GitDemonstrationView",
+          "options": {
+            "beforeMarkdowns": [
+              "使用`~`一次后退多步."
+            ],
+            "afterMarkdowns": [
+              "唰！如此简洁--相对引用就是好啊！"
+            ],
+            "command": "git checkout HEAD~4",
+            "beforeCommand": "git commit; git commit; git commit"
+          }
+        },
+        {
+          "type": "ModalAlert",
+          "options": {
+            "markdowns": [
+              "### Branch forcing",
+              "",
+              "你现在是相对引用的高手了，现在*用*他来实际做点事情。",
+              "",
+              "我使用相对引用最多的就是移动分支。你可以使用`-f`选项把直接让分支指向另一个提交亡灵。举个例子:",
+              "",
+              "`git branch -f master HEAD~3`",
+              "",
+              "（强制）移动master指向HEAD的第3级父提交。"
+            ]
+          }
+        },
+        {
+          "type": "ModalAlert",
+          "options": {
+            "markdowns": [
+              "要完成此关，移动`HEAD`，`master`和`bugFix`到目标所示的位置。"
+            ]
+          }
+        }
+      ]
     }
   }
-};
+};