add doc setup section

Author: brainrake

docs/mkdocs.yml

@@ -62,6 +62,7 @@ nav:
   - Getting Started:
       - Overview: getting-started/overview.md
   - Usage:
+      - Setup: usage/setup.md
       - Configure pool: usage/configure-pool.md
       - Generating keys: usage/generate-keys.md
       - Deploy: usage/deploy.md

docs/usage/setup.md

@@ -0,0 +1,28 @@
+## Installation
+
+Follow [this guide](https://zero-to-nix.com/start/install) to Install nix with [flakes](https://nix.dev/concepts/flakes.html) enabled.
+
+### Binary cache
+
+You can optionally use this project's binary cache to skip building software and download it instead. Edit `/etc/nix/nix.conf` (or related settings in NixOS config) and merge the new values separated by spaces into the options:
+
+```
+substituters = ...  https://cache.staging.mlabs.city/spo-anywhere
+trusted-public-keys = ... spo-anywhere:bmI58BmXnmeuAtMKbm3qhwiJ1RALMfo6cDwncfaGa6Q=
+```
+
+## Start new project from flake
+
+Create a new directory, enter it, and initialize a new project form the spo-anywhere flake template.
+
+```
+mkdir my-spo
+cd my-spo
+nix flake init --template github:mlabs-haskell/spo-anywhere
+```
+
+Check that the installation script starts:
+
+```
+nix run .#install -- -h
+```