Update Readme

README.md

@@ -25,4 +25,17 @@ Read version from git tag and update git tag and print version to a go package n
 $ ./semver_version.sh -l go -f ./semantic_version/version.go
 ```
 
-...
+To trigger a major release use "[major]" keyword in your git commit message.
+Ex:
+
+```
+Add new feature abc [major]
+- line 1
+- line 2
+```
+
+Currently multiline messages merged into one line in the release command.
+For minor releases use "[minor]"
+Default release type is patch
+
+Build versions and pre-releases are not supported.