Format file format from Windows/dos to Unix (#1949)

### What problem does this PR solve?

Related source file is in Windows/DOS format, they are format to Unix
format.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

web/src/pages/add-knowledge/index.less

@@ -1,19 +1,19 @@
-.container {
-  display: flex;
-  height: 100%;
-  width: 100%;
-  .contentWrapper {
-    flex: 1;
-    overflow-x: auto;
-    height: 100%;
-    background-color: rgba(247, 248, 250, 1);
-    padding: 16px 20px 28px 40px;
-    display: flex;
-    flex-direction: column;
-  }
-  .content {
-    background-color: white;
-    margin-top: 16px;
-    flex: 1;
-  }
-}
+.container {
+  display: flex;
+  height: 100%;
+  width: 100%;
+  .contentWrapper {
+    flex: 1;
+    overflow-x: auto;
+    height: 100%;
+    background-color: rgba(247, 248, 250, 1);
+    padding: 16px 20px 28px 40px;
+    display: flex;
+    flex-direction: column;
+  }
+  .content {
+    background-color: white;
+    margin-top: 16px;
+    flex: 1;
+  }
+}