Expand README

README.md

@@ -1,9 +1,16 @@
 # Raft
 
 A Raft implementation in F#.
+It allows pluggable persistent-store back-ends and communication channels, but out of the box you get an in-memory store and a simulated network.
+
+You can play around with it via a command-line interface (`RaftExplorer`, which you can simply `dotnet run`), or a Fable web UI (`cd RaftFable && npm install && npm start`).
 
 # Development tips
 
+The Node ecosystem being what it is, it is *strongly* recommended that you use the associated Nix flake to give you an environment in which you can run the Fable UI.
+Simply `nix develop` (optionally `--profile .profile` if you want to persist the configuration into a [profile](https://nixos.org/manual/nix/stable/package-management/profiles.html) so that it doesn't get garbage-collected).
+If you're running on a non-`aarch64-darwin` platform, please feel free to contribute the appropriate changes to `flake.nix`; it should be easy to generalise using e.g. `flake-utils`.
+
 There are pull request checks on this repo, enforcing [Fantomas](https://github.com/fsprojects/fantomas/)-compliant formatting.
 After checking out the repo, you may wish to add a pre-push hook to ensure locally that formatting is complete, rather than having to wait for the CI checks to tell you that you haven't formatted your code.
 Consider performing the following command to set this up in the repo:

hooks/pre-push

@@ -9,8 +9,16 @@ def check_fantomas():
         raise Exception(f"Formatting incomplete (return code: {result.returncode}). Consider running `dotnet tool run fantomas -r .`")
 
 
+def check_alejandra():
+    result = subprocess.run(["alejandra", "--check", "--quiet", "*.nix"])
+    if result.returncode != 0:
+        print(result.stdout)
+        raise Exception(f"Formatting incomplete (return code: {result.returncode}). Consider running `alejandra *.nix`")
+
+
 def main():
     check_fantomas()
+    check_alejandra()
 
 
 if __name__ == "__main__":