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/progress/circular-progress-bar.vue

@@ -7,6 +7,7 @@
     <el-progress type="circle" :percentage="50" status="exception" />
   </div>
 </template>
+
 <style scoped>
 .demo-progress .el-progress--circle {
   margin-right: 15px;

docs/examples/progress/custom-color.vue

@@ -52,6 +52,7 @@ const decrease = () => {
   }
 }
 </script>
+
 <style scoped>
 .demo-progress .el-progress--line {
   margin-bottom: 15px;

docs/examples/progress/dashboard-progress-bar.vue

@@ -44,6 +44,7 @@ onMounted(() => {
   }, 500)
 })
 </script>
+
 <style scoped>
 .demo-progress .el-progress--line {
   margin-bottom: 15px;

docs/examples/progress/indeterminate-progress.vue

@@ -21,6 +21,7 @@
 <script lang="ts" setup>
 const format = (percentage) => (percentage === 100 ? 'Full' : `${percentage}%`)
 </script>
+
 <style scoped>
 .demo-progress .el-progress--line {
   margin-bottom: 15px;