Proxy API to avoid CORS problems during JS development

Caddyfile

# Proxy API to avoid CORS problems during development :
# - Get Caddy from https://caddyserver.com/
# - Put the Caddyfile somewhere with the Caddy executable
# - Change posts, paths, ... as needed
# - Start the Caddy process (without args)
# - Lauch the SPA using the URL http://localhost:8081

localhost:8081 
log stderr

# First : the API
proxy /api http://myserver.foo.bar

# Last : the dev server started by npm, yarn, ...
proxy / localhost:8080