fix(预处理组件): 限制上传文件类型

- 限制可上传文件类型为.xlsx,.doc,.docx,.pdf,.txt

src/views/knowledge/detail/components/preprocessing.vue

@@ -132,6 +132,10 @@ export default {
     createFiled() {
       let input = document.createElement('input')
       input.type = 'file'
+
+      // 对文件的类型做出限制
+      input.accept = '.xlsx,.doc,.docx,.pdf,.txt'
+
       input.onchange = e => {
         // this.$emit('getFile', e.target.files[0])
         this.filed = e.target.files[0]