doc minimum gradle version

Author: hauner

README.md

@@ -4,7 +4,7 @@
 # com.github.hauner.openapi.gradle 
 
 a gradle plugin based on the [openapi-generatr-api][generatr-api] to handle all configured openapi-generatrs
-without explicit dependency on a generatr.
+without explicit dependency on a generatr. Requires Gradle 5.2 or better.
 
 # Usage
 

build.gradle

@@ -49,7 +49,7 @@ gradlePlugin {
         generatrPlugin {
             id = 'com.github.hauner.openapi-generatr'
             displayName = 'Gradle openapi-generatr plugin'
-            description = 'plugin to run openapi-generatr-x generators, e.g. openapi-generatr-spring'
+            description = 'plugin to run openapi-generatr-x generators, e.g. openapi-generatr-spring (requires gradle 5.2+)'
             implementationClass = 'com.github.hauner.openapi.gradle.OpenApiGeneratrPlugin'
         }
     }