conf.py: uncommented path  finding for sphinx to find docs folder.
index.rst: Added modules.rst as an overview.
make.bat, Makefile, pyramid.rst: Deleted!
utils: put many functions in convenience.py
environment.py: Added stuff for documentation
README.md: deleted badges (directly on GitLab now!)
setup.py: Further streamline!

put most options into setup.cfg

Added environment.yml and requirement.txt.
GitLab should now produce html coverage artifacts.
io_vectordata: now warns if grid spacing is not equal in all directions.