Introduce dev version suffix
During %"0.8.0" development it wasn’t clear which version we were using between the one installed from pip and the local one in your Poetry devenv.
I propose to use `0.9.0dev` when branching.
It might be necessary to handle this temporary version format: in `release.sh` and elsewhere.
Actually, it just requires to comment `commit_tag` line in `release.sh`.
issue