Update add-to-xml.md

Author: Arashvscode

docs/add-to-xml.md

@@ -3,7 +3,7 @@
 It's easy to add CodeView in your XML layout, notes that CodeView is based on AppCompatMultiAutoCompleteTextView,
 so you can easily customize it like any AutoCompleteTextView
 
-```
+``` xml
 <com.amrdeveloper.codeview.CodeView
     android:id="@+id/codeView"
     android:layout_width="match_parent"
@@ -13,4 +13,4 @@ so you can easily customize it like any AutoCompleteTextView
     android:dropDownHorizontalOffset="0dp"
     android:dropDownSelector="@color/darkGrey"
     android:gravity="top|start" />
-```
+```