Update in README the link to the latest stable release #262

Hi! On Ubuntu 20.04, I found out that the link to the transpiler's *.jar file in README is outdated. So, I decided to run the freshest version from here. Unfortunately, I received:

Error: Could not find or load main class org.polystat.py2eo.transpiler.Main
Caused by: java.lang.ClassNotFoundException: org.polystat.py2eo.transpiler.Main

Here were my steps:

1. Create a file test.py in ./dir:

def myC():
    class c:
        value = 11
        def getValue(self): return self.value
    class d(c): pass
    o = d()
    return o.getValue() == 11

1. Download the transpiler into ./dir
2. Run .jar in ./dir

cd dir
java -jar py2eo*.jar test.py

Please, make the link refer to the latest stable version of the transpiler.