Add release.md file

Author: StefMa

RELEASE.md

@@ -0,0 +1,30 @@
+## How to release
+
+* Checkout the master branch
+```
+git checkout master
+```
+* Change version in [`build.gradle.kts`](build.gradle.kts)
+* Commit changes 
+```
+git commit -m "Bump version"
+```
+* Release to bintray without testing (`master` branch should be tested)
+```
+./gradlew clean build bintrayUpload -PdryRun=false -x test
+ ```
+ * Create the tag
+ ```
+ git tag v[VER.SI.ON]
+ ```
+ * Push the previous created tag
+ ```
+  git push origin v[VER.SI.ON]
+  ```
+ * Create the GitHub release
+ * Add version back ([`build.gradle.kts`](build.gradle.kts)) to `-NOSNAPSHOT`
+ * Push the master branch
+ ```
+git push origin master
+```
+