Add links to changelog

Author: dedemorton

CHANGELOG.md

@@ -1,9 +1,9 @@
 ## 5.1.6
- - Docs: Fix broken link by removing extra space. 
+ - Docs: Fixed broken link by removing extra space. [#347](https://github.com/logstash-plugins/logstash-input-beats/pull/347)
 
 ## 5.1.5
  - Docs: Fixed section ID that was causing doc build errors in the versioned
-plugin docs. 
+plugin docs. [#346](https://github.com/logstash-plugins/logstash-input-beats/pull/346)
 
 ## 5.1.4
  - Added `add_hostname` flag to enable/disable the population of the `host` field from the beats.hostname field [#340](https://github.com/logstash-plugins/logstash-input-beats/pull/340)