Added documentation for the new sortReset method

site/docs/api/methods.md

@@ -522,6 +522,15 @@ The calling method syntax: `$('#table').bootstrapTable('method', parameter)`.
 
 - **Example:** [Sort By](https://examples.bootstrap-table.com/#methods/sort-by.html)
 
+## sortReset
+
+- **Parameter:** `undefined`
+
+- **Detail:**
+
+  Resets sort state of the table regardless of whether caused by the user or programmatically.
+
+- **Example:** [Sort reset](https://examples.bootstrap-table.com/#methods/sort-reset.html)
 
 ## toggleDetailView