py: add install from pypi

Author: milahu

py/readme.md

@@ -4,10 +4,18 @@ python jobclient and jobserver for the GNU make tokenpool protocol
 
 ## install
 
+install from [github](https://github.com/milahu/gnumake-tokenpool)
+
 ```
 pip install git+https://github.com/milahu/gnumake-tokenpool
 ```
 
+or install from [pypi](https://pypi.org/project/gnumake-tokenpool/)
+
+```
+pip install gnumake-tokenpool
+```
+
 ## usage
 
 ```py