Updating readme to be more clear w/upstream sunset

Since the upstream is sunsetting but it seems development is continuing here I thought it might be a good idea to update the readme to be more clear with the note at the top that it means the upstream Atom repo's and not the atom-community ones or whatever this may end up being called in the future.

Author: kaosine

README.md

@@ -2,7 +2,7 @@
 
 [![Build status](https://dev.azure.com/github/Atom/_apis/build/status/Atom%20Production%20Branches?branchName=master)](https://dev.azure.com/github/Atom/_build/latest?definitionId=32&branchName=master)
 
-> Atom and all repositories under Atom will be archived on December 15, 2022. Learn more in our [official announcement](https://github.blog/2022-06-08-sunsetting-atom/)
+> Due to changes in focus The upstream Atom  and all it's repositories under the original Atom branding will be archived on December 15, 2022. Get involved here while we work on the future of Atom-community. You can learn more in their [official announcement](https://github.blog/2022-06-08-sunsetting-atom/) and get involved here.
 
 Atom is a hackable text editor for the 21st century, built on [Electron](https://github.com/electron/electron), and based on everything we love about our favorite editors. We designed it to be deeply customizable, but still approachable using the default configuration.