@netlify/config: Support _header files

[RaeesBhatti]

Which problem is this feature request solving?

Support Netlify's _headers files where @netlify/config package is used.

Describe the solution you'd like

We parse the _headers file and merge the rules with the rules defined in netlify.toml.

Describe alternatives you've considered

• Keeping _headers files parsing in a different package
• Providing a separate interface in @netlify/config to parse _headers file manually

Can you submit a pull request?

Yes

[verythorough]

Noting that this change would allow plugins to modify site headers. I don't think we'll get to this in Q1; moving to Icebox for now.

[erezrokah]

More context:

1. Netlify CLI currently has code duplicated from our production logic to parse headers.
2. It would be nice to use a similar approach to ntl dev --edgeHandlers that delegates redirects/headers/any other production logic to a dedicated library

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in 1 year. It will be closed in 14 days if no further activity occurs. Thanks!

[github-actions[bot]]

This issue was closed because it had no activity for over 1 year.