Development environment

• devenv configuration to create a LXC container
• Install npm global with yarn (needed by the backend) and pnpm (needed by Etherpad)
• Install PostgreSQL, create the users and the DBs needed by the backend and Etherpad
• Install Etherpad
• Update the README

roles/deploy/templates/env.j2

 # Frontend
 REACT_APP_BASE_URL=https://acoords-test.devs.coop/api
+REACT_APP_WS_URL =ws://acoords-test.devs.coop/ws
 
 # Backend
 DBAPI=postgresql://{{ database_user }}:{{ database_password }}@localhost/{{ database_name }}