fix typo

README.adoc

@@ -43,7 +43,7 @@ As component select `Documentation`.
 If you would like to contribute, please fork this repository and send
 pull requests. To contribute to the latest development version, use the
 `develop` branch for your edits! Documentation for already released
-version can be found in the respective maintenance branches. +
+versions can be found in the respective maintenance branches. +
 Contributors with direct access to the repository are encouraged to use the
 git-flow-avh workflow (package `git-flow-avh`). However, this is not a must.
 For help on style and structure, refer to the https://doc.opensuse.org/products/opensuse/Styleguide/opensuse_documentation_styleguide_sd/[Documentation Styleguide]