add v1.0.0 info to legacy docs

docs/index.md

@@ -1,4 +1,12 @@
-<img src="assets/hyperglass-dark.png" width=300></img>
+<img src="assets/hyperglass-dark.png" width=300/>
+
+# Version 1.0
+
+**These docs are for the original release of hyperglass (now called v0)**.
+
+Following the positive response hyperglass v0, version 1.0 of hyperglass has been in development for nearly a year, with an active, but quiet, public beta since March 2020. Version 1.0 features significant backend performance and security improvements, a brand new even more modern UI, built-in support for more Network Operating Systems, and much more.
+
+**If you're considering hyperglass for your network, or are still using v0, please check out the [v1.0.0 repository](https://github.com/checktheroads/hyperglass) or the [new docs site](https://hyperglass.io)**.
 
 # What is hyperglass?