docs: add some basic information on readme

README.md

@@ -1 +1,41 @@
 # sortedl1
+
+**sortedl1** is a python package for Sorted L-One Penalized Estimation.
+
+## Installing
+
+sortedl1 is currently only available on github. To install it, run
+
+```python
+pip install -U git+https://github.com/jolars/sortedl1
+```
+
+# Usage
+
+Estimators in **sortedl1** are compatible with the scikit-learn interface.
+
+```python
+import numpy as np
+from numpy.random import default_rng
+
+from sortedl1 import Slope
+
+n = 100
+p = 3
+
+seed = 31
+rng = default_rng(seed)
+
+x = rng.standard_normal((n, p))
+beta = rng.standard_normal(p)
+y = x @ beta + rng.standard_normal(n)
+
+model = Slope()
+model.fit(x, y)
+
+print(model.coef_)
+```
+
+## Contributing
+
+The backbone of the package is written in C++ and developed in a separate repository at <https://github.com/jolars/libslope>. So if you have any issues with the package other than such that are specific to the python interface, please report them there. But feel free to request features here.