Provide more examples / detailed docs on custom request header override per spider #176
Description
I have a situation where I need to supply a custom consent cookie to a specific spider. While it is described how to do it for the middleware, it is not very clear still how to pass e.g. custom headers to the init/1 callback of Crawly.Spider.
Even a small example or such will help and can help with writing a good example in docs, thanks!