update readme to markdown

Author: countableSet

README.adoc

@@ -0,0 +1,13 @@
+# Semantic Version Gradle Plugin
+
+* [docs](https://github.com/countableSet/semantic-version-plugin/tree/main/docs)
+* [gradle plugin portal](https://plugins.gradle.org/plugin/dev.poolside.gradle.semantic-version)
+
+Based on a given `major.minor` version, plugin determines patch version based on what is already maven repository by auto incrementing it to produce the next version number. Major or minor versions must be manually changed.
+
+```groovy
+plugins {
+    id 'maven-publish'
+    id 'dev.poolside.gradle.semantic-version' version '<version>'
+}
+```

README.md

@@ -31,7 +31,7 @@ gradlePlugin {
             displayName = "Poolside Semantic Version Plugin"
             description = "Based on a given major.minor version, plugin determines patch version based on what is already " +
                     "maven repository by auto incrementing it to produce the next version number. Major or minor versions " +
-                    "must be manually changed"
+                    "must be manually changed."
             tags.set(listOf("semantic version", "maven", "publish", "auto increment"))
         }
     }