trim md文本，防止识别为代码

src/views/exam/components/MarkdownText.vue

@@ -1,5 +1,5 @@
 <template>
-  <div v-html="markdownToHTML(raw)" class="markdown-content"></div>
+  <div v-html="markdownToHTML(trimmedRaw)" class="markdown-content"></div>
 </template>
 
 <script lang="ts">
@@ -11,8 +11,16 @@ export default Vue.extend({
   props: {
     raw: String
   },
+  data() {
+    return {
+      trimmedRaw: ''
+    }
+  },
   methods: {
     markdownToHTML
+  },
+  mounted() {
+    this.trimmedRaw = this.raw.trim()
   }
 })
 </script>