refactor: Spelling mistakes.

Author: leezng

example/App.vue

@@ -16,7 +16,7 @@
 
     <div class="example-box">
       <h2 class="title">
-        Selecter
+        Selector
       </h2>
       <select-control />
     </div>

src/components/TreeNode/index.vue

@@ -2,7 +2,7 @@
   <div
     :class="{
       'vjs-tree__node': true,
-      'has-selecter': showSelectController,
+      'has-selector': showSelectController,
       'is-highlight': highlightSelectedNode && checked
     }"
     @click="onTreeNodeClick"

src/components/TreeNode/styles.less

@@ -8,8 +8,8 @@
   display: flex;
   position: relative;
 
-  &.has-selecter {
-    padding-left: @selecter-span;
+  &.has-selector {
+    padding-left: @selector-span;
   }
 
   &.is-highlight,

src/themes.less

@@ -23,4 +23,4 @@
 @border-color: #bfcbd9;
 
 /* 左侧可选区域占用空间 */
-@selecter-span: 30px;
+@selector-span: 30px;