README.md: Note Elements requirement.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
9 years ago · 376e5bb584
1 changed files with 3 additions and 0 deletions
--- a/README.md
+++ b/README.md
@ -7,6 +7,9 @@ definition file).
 There are command line utilities to create and process various packets
 in [test-cli](test-cli/HOWTO-USE.md).

+It requires features not currently in bitcoin, so it runs on top of
+the sidechain [Elements Alpha](https://github.com/ElementsProject/elements)
+
 This is very much a testbed and work in progress; expect All The
 Things to change, all the time.