Add pip support

[derTPK]

Steps to add pip support:
add pyproject.toml

[build-system]
requires = ["setuptools>=62"]
build-backend = "setuptools.build_meta"

and setup.cfg

[metadata]
name = bayseg
version = 0.0.1
author = Alexander Schaaf
author_email = a.schaaf@abdn.ac.uk
description = An unsupervised machine learning algorithm for the segmentation of spatial data sets. 
long_description = file: README.md
long_description_content_type = text/markdown
url = https://github.com/cgre-aachen/bayseg
project_urls =
    Bug Tracker = https://github.com/cgre-aachen/bayseg/issues
classifiers =
    Programming Language :: Python :: 3
    License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)
    Operating System :: OS Independent

[options]
package_dir =
	= src
packages = find:
python_requires = >=3.6
install_requires = 
	pytest
	scipy
	numpy
	pandas
	matplotlib
	tqdm
	scikit_learn

[options.packages.find]
where = src

move the directory bayseg to the src directory

see also:
https://git.rwth-aachen.de/Till.Petersen-Krauss/bayseg