Unsub Documentation Update

[Scott Chamberlain]

Hi all!

We've got a documentation update!  Documentation is always important for any technical product, and Unsub is no exception. 

Here's the details of the changes:

- Documentation now lives at https://docs.unsub.org

- Links to documentation throughout https://unsub.org have been updated for a little while now (changed from help.unsub.org to docs.unsub.org)

- We've re-organized Unsub documentation following the Divio documentation system. We now have five major sections: Tutorials, How-to guides, Reference, How it works, and Troubleshooting. At the landing page for each section you'll find a description of the section. 

- One benefit of the change in documentation platform (now using GitBook) is consistency with another of our major products - OpenAlex - that also uses GitBook. You can find the OpenAlex docs at https://docs.openalex.org

- Another benefit is that we have greater flexibility in content we can put on any individual page - which we think will make Unsub documentation better

Note that Unsub documentation - as all software documentation - is a work in progress. 

We'd love your feedback. If you have any thoughts on the new documentation - anything that you think is missing or could be improved - let us know at sup...@unsub.org 

Thanks! Scott