docs(examples): standardize unified code format and fix some type (#16370)

* docs: standardize unified example code format and fix some example type

* docs:  update some example type

* Update docs/examples/descriptions/sizes.vue

Co-authored-by: kooriookami <38392315+kooriookami@users.noreply.github.com>

* docs: update example-page-header

* docs: update example-page-header

---------

Co-authored-by: kooriookami <38392315+kooriookami@users.noreply.github.com>

docs/examples/button/custom.vue

@@ -8,8 +8,8 @@ import { isDark } from '~/composables/dark'
     <el-button color="#626aef" :dark="isDark" plain>Plain</el-button>
 
     <el-button color="#626aef" :dark="isDark" disabled>Disabled</el-button>
-    <el-button color="#626aef" :dark="isDark" disabled plain
-      >Disabled Plain</el-button
-    >
+    <el-button color="#626aef" :dark="isDark" disabled plain>
+      Disabled Plain
+    </el-button>
   </div>
 </template>

docs/examples/button/link.vue

@@ -6,8 +6,9 @@
       :key="button.text"
       :type="button.type"
       link
-      >{{ button.text }}</el-button
     >
+      {{ button.text }}
+    </el-button>
   </div>
 
   <p>Disabled link button</p>
@@ -18,8 +19,9 @@
       :type="button.type"
       link
       disabled
-      >{{ button.text }}</el-button
     >
+      {{ button.text }}
+    </el-button>
   </div>
 </template>
 

docs/examples/button/text.vue

@@ -6,8 +6,9 @@
       :key="button.text"
       :type="button.type"
       text
-      >{{ button.text }}</el-button
     >
+      {{ button.text }}
+    </el-button>
   </div>
 
   <p>Background color always on</p>
@@ -18,8 +19,9 @@
       :type="button.type"
       text
       bg
-      >{{ button.text }}</el-button
     >
+      {{ button.text }}
+    </el-button>
   </div>
 
   <p>Disabled text button</p>
@@ -30,8 +32,9 @@
       :type="button.type"
       text
       disabled
-      >{{ button.text }}</el-button
     >
+      {{ button.text }}
+    </el-button>
   </div>
 </template>