docs: tag message from configuration (#453)

Author: ebAtUelzener

docs/configuration/overview.md

@@ -38,6 +38,7 @@ All `axion-release-plugin` configuration options:
             serialize({ tag, version -> ... }) // creates tag name from raw version
             deserialize( { tag, position, tagName -> ... }) // reads raw version from tag
             initialVersion({ tag, position -> ... }) // returns initial version if none found, 0.1.0 by default
+            messageCreator({ position, version, previousVersion -> ... }) // returns tag message, empty String (default) means no message
         }
 
         nextVersion { // doc: Next version markers

docs/configuration/version.md

@@ -197,6 +197,19 @@ that will construct initial version:
 
 Input objects have same structure as deserialization closure inputs.
 
+### Tag message
+
+The default message creator will skip adding a message by returning an empty string.
+
+You can implement your own message creator by setting a closure that would accept
+position in SCM, current version and previous version:
+
+    scmVersion {
+        tag {
+            messageCreator({position, version, previousVersion -> ...})
+        }
+    }
+
 ## Incrementing
 
 Incrementing phase does increment the version in accordance with

docs/examples/examples.md

@@ -56,6 +56,7 @@ scmVersion {
         // configure via function calls
         deserializer({ tagProperties, scmPosition, String -> "tag" })
         serializer({ tagProperties, version -> "tag" })
+        messageCreator({ scmPosition, version, previousVersion -> "message" })
     }
     repository {
         type.set("git")