Merge pull request #1 from obsidiansystems/ch1bo/show-demo

Add a screenshot of the demo and define a .gitignore

.gitignore

@@ -0,0 +1,4 @@
+# Directories produced by demo
+demo-logs/
+tmp/
+devnet/

README.md

@@ -8,9 +8,11 @@ It allows starting and closing a head with an arbitrary number of nodes, each wi
 To run the demo enter a Nix shell and run it with `cabal`:
 
 ```
- $ nix-shell -A shells.ghc default.nix
- $ cabal run
+nix-shell -A shells.ghc default.nix --option substituters "https://cache.nixos.org https://cache.iog.io https://nixcache.reflex-frp.org" --option trusted-public-keys "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= ryantrinkle.com-1:JJiAKaRv9mWgpVAz8dwewnZe0AzzEAzPkagE9SP5NWI="
+
+cabal run
 ```
 
 The demo can then be viewed in **Chrome**(*Chrome must be used at this time because of a limitation in JSaddle*) at `http://localhost:3003/`.
 
+![](./demo.png)