Added numpy as a build-system requirement and updated readme to pip i…

…nstall.

README.md

@@ -64,12 +64,17 @@ g++ -I../main example.C -o example -O3
 
 # Getting started (Python)
 
-On MacOS, do the following (not yet made on other ).
+```bash
+pip install git+https://github.com/hbf/miniball.git#subdirectory=python
+```
+
+or
 
-1. Stand in the `python`-folder.
-2. Run `pip install setup.py` (you may need to use the `--user` option or `sudo`).
-3. Run `pytest` (if you do not have it, install it through `pip install pytest`) to see that it works and that all tests pass.
-4. Does it work? Great! You are now ready to use the python function.
+```bash
+git clone https://github.com/hbf/miniball.git
+cd miniball/python
+pip install .
+```
 
 # Getting started (C#)
 

python/pyproject.toml

@@ -0,0 +1,6 @@
+[build-system]
+requires = [
+    "setuptools",
+    "wheel",
+    "numpy",
+]