Include a folder in package.zip

How to include a folder in package.zip? I tried
custom:
package:
sources:
"./":
- “handler.js”
"./config/":
- “**” # Include everything

but this moved my config/default.json into the top level.
Also, am I supposed to put node_modules in there?
Something recently changed, I had this working earlier without having to configure any of this.