name: header
long: header
short: H
value: NAME:VALUE
help: Pass custom header(s) to server
help_heading: HTTP options
multi: append
config_file: true
env_var: HURL_HEADER='name1:value1|name2:value2' (headers are separated by |)
---
Add an extra header to include in information sent. Can be used several times in a command.

Do not add newlines or carriage returns.
