added refresh analyzer

Author: ashwinkumar12345

docs/ism/refresh-analyzer.md

@@ -0,0 +1,16 @@
+---
+layout: default
+title: Refresh Search Analyzer
+parent: Index State Management
+nav_order: 6
+---
+
+# Refresh search analyzer
+
+With ISM installed, you can refresh search analyzers in real time with the following API:
+
+```json
+POST /_opendistro/_refresh_search_analyzers/<index or alias or wildcard> 
+```
+
+For example, if you change the synonym list in your analyzer, the change takes effect without you needing to close and reopen the index.