Update install info

Author: ZakaHaceCosas

docs/manual/install.md

@@ -20,20 +20,25 @@ Copy and paste the following code in a terminal session.
 curl -fsSL fuckingnode.github.io/install.sh | bash
 ```
 
-### NixOS
+### Nix / NixOS
+
+!!! warning
+    ARM (`aarch64-linux`) support is available, but NOT tested!
 
 Add the repo to your `flake.nix`.
 
 ```nix
 inputs = {
+    ...
     fuckingnode.url = "github:FuckingNode/FuckingNode";
-}
+    ...
+};
 ```
 
 Then, add this to your system packages:
 
 ```nix
-inputs.fuckingnode.packages."${pkgs.system}".default
+inputs.fuckingnode.packages."${pkgs.system}".default;
 ```
 
 ## Compile from source