[documentation] Add known issues + project links in readme and docs (#541)

README.md

@@ -33,6 +33,9 @@ Here's a screenshot of the instance landing page!
 - [Wishlist](#wishlist)
 - [Getting Started](#getting-started)
 - [Third-Party Packaging](#third-party-packaging)
+- [Known Issues](#known-issues)
+  - [Client App Issues](#client-app-issues)
+  - [Federation Issues](#federation-issues)
 - [Contributing](#contributing)
 - [Contact](#contact)
 - [Credits](#credits)
@@ -173,6 +176,18 @@ Thank you so much to the cool people who have put time and energy into packaging
 
 These packages are not maintained by GoToSocial, so please direct questions and issues to the repository maintainers (and donate to them!).
 
+## Known Issues
+
+Since GoToSocial is still in alpha, there are plenty of bugs. We use Github issues to track these. [Check them out here](https://github.com/superseriousbusiness/gotosocial/issues?q=is%3Aissue+is%3Aopen+label%3Abug).
+
+### Client App Issues
+
+GoToSocial works great with Tusky and Pinafore, but some other client applications still need work or have issues connecting to GoToSocial. We're tracking them [right here](https://github.com/superseriousbusiness/gotosocial/projects/5). It's our goal to make any app that's compatible with the Mastodon API work seamlessly with GoToSocial.
+
+### Federation Issues
+
+Since every ActivityPub server implementation has a slightly different interpretation of the protocol, some servers don't quite federate properly with GoToSocial yet. We're tracking these issues [in this project](https://github.com/superseriousbusiness/gotosocial/projects/4). Eventually we want to make sure that any implementation that can federate nicely with Mastodon should also be able to federate with GoToSocial.
+
 ## Contributing
 
 You wanna contribute to GtS? Great! ❤️❤️❤️ Check out the issues page to see if there's anything you wanna jump in on, and read the [CONTRIBUTING.md](./CONTRIBUTING.md) file for guidelines and setting up your dev environment.