📝 update contributing description (#9)

CONTRIBUTING.md

@@ -6,7 +6,7 @@ Please note we have a [code of conduct](./.github/CODE_OF_CONDUCT.md), please fo
 
 ## Pull Request Process
 
-1. Ensure any install or build dependencies are removed before the end of the layer when doing a build.
-1. Update the README.md with details of changes to the interface, this includes new environment variables, exposed ports, useful file locations and container parameters.
-1. Increase the version numbers in any examples files and the README.md to the new version that this Pull Request would represent. The versioning scheme we use is [SemVer](http://semver.org/).
+1. Make sure that the thesis can be built completely and look at the result. Make sure that you do not make any mistakes, e.g. spelling mistakes.
+1. Check if the README.md needs to be updated with the changes made.
+1. Increase the version number in any necessary files to the new version that the pull request would represent if it is a major or important change. The versioning scheme we use is [SemVer](http://semver.org/).
 1. You may merge the Pull Request in once you have the sign-off of one other developers, or if you do not have permission to do that, you may request the reviewer to merge it for you.