Information to add in the wiki for manual installation

When installing manually (I cannot use conda for my project), I had a problem when installing JCC in my virtual environment.
I had the message

jcc3/sources/jcc.cpp:25:10: fatal error: Python.h: No such file or directory
     #include <Python.h>

in fact I need to install python-dev (in fact python3-dev as I am using Python3):
sudo apt install python(3)-dev
to solve the problem.

in the manual installation page, it is said to use the version 2.7 whereas in the Installation (with Conda) a snapshot shows a 3.X version. On Ubuntu, the virtual environment says that the 2.7 is no more maintained …