Documentation
* docs: add developer installation instructions
Now that the repository should be pip installed with -e for
developers, add instructions to reflect this. ([`7677a85`](https://github.com/siemdejong/ithappens/commit/7677a85a34f10cf1632e35559a539b6f24470151))
Feature
* feat: delete standard adding to python path
Adding to python path is considered bad practice.
Use `python -m pip install -e .` in the root directory to
install the package in developer mode and add it to the python path. ([`113cdf2`](https://github.com/siemdejong/ithappens/commit/113cdf298cc91fdb59c7f983736e085d3bc30bda))