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

inventory/host_vars/acoords-test.devs.coop/etherpad.yml

+---
+etherpad_url: "https://acoords.devs.coop"
+etherpad_ip: "127.0.0.1"
+etherpad_trust_proxy: "true"
+etherpad_disable_ip_logging: "false"
+etherpad_users:
+  - name: admin
+    password: "admin"
+    is_admin: "true"
+etherpad_api_key: !vault |
+          $ANSIBLE_VAULT;1.1;AES256
+          63616132633734326634336361663830393732303037653837363832613063353961663633373030
+          6437623830626266343161643338613761386339373061380a336135633237613064316632333062
+          33306265313133393831316635613063623930393334353761633463336661383534613262326131
+          3637356235633735300a383539323261333538653937336331626636353739636239396435396632
+          66336433376663353032656164623731373866643463323837633630383332306662
+etherpad_database_host: localhost
+etherpad_database_name: etherpad
+etherpad_database_user: etherpad
+etherpad_database_password: !vault |
+          $ANSIBLE_VAULT;1.1;AES256
+          61333738356165306366623534623366333162663165613236663962633834613535356666353262
+          6534326232346362306336363766623764353637393433310a346338616439363365643935353431
+          32383963343537393837633135383937336130663333363461646663343966353939303663343363
+          6639303934313465640a376639646433646136636233623664326235343638396666376234306336
+          32633036613732633234666337616633363638373363393061616437333932363863