Add apollo-link-observable to community links

[dragozin]

PR description

Add information about apollo-link-observable to client docs.

About the link

Link that allows you to make side effects of graphql queries using RxJS

Motivation for creating the link

1. Organization of application side effects such as logging, accessing the browser cache, recording analytics events etc.
2. A part of the application with longer lifecycle than a component's one.
3. Creating a complex application business logic.
4. Performing REST queries as a reaction to the graphql query.
5. Local state changes that are triggered by graphql queries.

Checklist:

• If this PR is a new feature, please reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests

[apollo-cla]

@dragozin: Thank you for submitting a pull request! Before we can merge it, you'll need to sign the Apollo Contributor License Agreement here: https://contribute.apollographql.com/

[jpvajda]

Thanks for wanting to add this to our community links, I had a question for you.

It's currently tagged as release 0.0.1 and there is no description and no recent updates to the code. I wanted to check if this project is still supported and if you could validate it's ready to be publicly shared within our community links as it might drive a lot of interest to the project.

[dragozin]

Hi, @jpvajda!

Thank you for your interest in my PR! This is the first release and I'm using the link in my projects. I suppose it might be helpful to other people. I have a description with motivation and examples of use here : https://github.com/dragozin/apollo-link-observable#readme . The project is currently supported by me.

[jpvajda]

@dragozin Thanks for the quick response! We'd be happy to add it to the community links! Thanks for putting in the effort to help Apollo Client users leverage RxJS.