readme format changed

Author: ulf1

README.md

@@ -1,10 +1,12 @@
-# fracdiff
+[![PyPI version](https://badge.fury.io/py/numpy-fracdiff.svg)](https://badge.fury.io/py/numpy-fracdiff)
+
+# numpy-fracdiff
 Fractional Difference for Time Series
 
 ## Installation
 The `numpy-fracdiff` [git repo](http://github.com/ulf1/numpy-fracdiff) is available as [PyPi package](https://pypi.org/project/numpy-fracdiff)
 
-```
+```sh
 pip install numpy-fracdiff
 pip install git+ssh://git@github.com/ulf1/numpy-fracdiff.git
 ```
@@ -13,10 +15,11 @@ pip install git+ssh://git@github.com/ulf1/numpy-fracdiff.git
 Check the [examples](https://github.com/ulf1/fracdiff/tree/master/examples) folder for notebooks.
 
 
-## Commands
-Install a virtual environment
+## Appendix
 
-```
+### Install a virtual environment
+
+```sh
 python3.6 -m venv .venv
 source .venv/bin/activate
 pip install --upgrade pip
@@ -25,16 +28,16 @@ pip install -r requirements.txt
 
 (If your git repo is stored in a folder with whitespaces, then don't use the subfolder `.venv`. Use an absolute path without whitespaces.)
 
-Python commands
+### Python commands
 
 * Jupyter for the examples: `jupyter lab`
 * Check syntax: `flake8 --ignore=F401 --exclude=$(grep -v '^#' .gitignore | xargs | sed -e 's/ /,/g')`
 * Run Unit Tests: `pytest`
 * Upload to PyPi with twine: `python setup.py sdist && twine upload -r pypi dist/*`
 
-Clean up 
+### Clean up 
 
-```
+```sh
 find . -type f -name "*.pyc" | xargs rm
 find . -type d -name "__pycache__" | xargs rm -r
 rm -r .pytest_cache