fix: better project base path detection

[MarcinVaadin]

Description

Do not use project.basePath for detecting project root.

From IntelliJ java docs:

   * <p>It's <b>strongly recommended</b> to use other methods instead of this one (see {@link #getBaseDir()} for alternatives. Most
   * probably any use of this method in production code may lead to unexpected results for some projects (e.g. if {@code .idea} directory is
   * stored not near the project files).
   * </p>

Fixes #47

[github-actions]

Artifact build on last commit: distributions.zip.
For MacOS users: there is a zip inside this zip and Finder unzips them both at once. Use unzip distributions.zip from Terminal or check solution for Archive Manager.

[MarcinVaadin]

Might be not needed if user accepts #115