README: project status update

Author: japaric

README.md

@@ -4,6 +4,24 @@
 
 **Status:** Proof of Concept. Do not use in production.
 
+Thanks for checking out our work! We wrote this PoC to test out the [compiler work] we did to enable the use of async/await in `no_std` code.
+
+[compiler work]: https://github.com/rust-lang/rust/pull/69033
+
+We don't intend to continue to work on this repository, or accept pull requests, for the time being but you are more than welcome to use it as a reference! The code is permissively licensed (MIT / Apache-2).
+
+If you are interested in using the async/await in your embedded project or evaluate it for a project, [give us a call]! We do consulting.
+
+[give us a call]: https://ferrous-systems.com/#contact
+
+To learn more about embedded async/await work check out this series of blog posts we wrote on the topic:
+
+- [Bringing async/await to embedded Rust](https://ferrous-systems.com/blog/embedded-async-await/) 
+- [async/await on embedded Rust](https://ferrous-systems.com/blog/async-on-embedded/)
+- [no_std async/await - soon on stable](https://ferrous-systems.com/blog/stable-async-on-embedded/)
+
+---
+
 Check `nrf52/examples` for an overview of what can be done with the runtime.
 
 **NOTE** You need a rustc build that includes PR [rust-lang/rust#69033]