Use a more specific heading per PR feedback.

Improving header per @vossad01 and @Relequestual's suggestion on the PR.

My apologies for the edit, but it's been nearly a month and I'd rather pull in the change than reject it.

Author: handrews

implementations.md

@@ -131,7 +131,7 @@ Schema generation
     -   <a href="http://schemaguru.snowplowanalytics.com/" id="link-impl-guru-ui">Schema Guru Web UI</a> - derives precise Schemas using several JSON instances. Based on [Schema Guru](link-impl-guru)
 -   Visual Studio
     -   <a href="http://visualstudiogallery.msdn.microsoft.com/b4515ef8-a518-41ca-b48c-bb1fd4e6faf7" id="link-impl-vs">JSON Schema Generator</a> - free extension
--   UML
+-   Sparx Enterprise Architect
     -   <a href="https://github.com/bayeslife/api-add-in" id="link-impl-uml">API-Add-In</a> - Sparx EA extension for exporting JSON Schema from UML models
 
 Data parsing