Replace bash process with languagetool java process

Especially when languagetool is run as a server (like with the provided systemd service) both the bash and the java process are running. Bash is not required anymore after the startup so it could be replaced by the java process itself.

I did not add exec for the help commands as they are using pipes.

Hint: I don't seem to be able to push from the command line, only from the web GUI (remote: GitLab: Committer '…' is not a member of team) so maybe this shouldn't be merged and rather recreated from an actual Arch maintainer? Still thought its more helpful to provide the actual change instead of just an issue.