docs: add build instructions to README

README.md

@@ -7,6 +7,86 @@ Hosts: [outfoxxed's gitea], [github]
 [outfoxxed's gitea]: https://git.outfoxxed.me/outfoxxed/quickshell
 [github]: https://github.com/outfoxxed/quickshell
 
+Documentation can be built from the [quickshell-docs](https://git.outfoxxed.me/outfoxxed/quickshell-docs) repo,
+though is currently pretty lacking.
+
+# Installation
+
+## Nix
+This repo has a nix flake you can use to install the package directly:
+
+```nix
+{
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+
+    quickshell = {
+      url = "git+https://git.outfoxxed.me/outfoxxed/quickshell";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+}
+```
+
+Quickshell's binary is available at `quickshell.packages.<system>.default` to be added to
+lists such as `environment.systemPackages` or `home.packages`.
+
+## Manual
+
+If not using nix, you'll have to build from source.
+
+### Dependencies
+To build quickshell at all, you will need the following packages (names may vary by distro)
+
+- just
+- cmake
+- pkg-config
+- ninja
+- Qt6 [ QtBase, QtDeclarative ]
+
+To build with wayland support you will additionally need:
+- wayland
+- wayland-scanner (may be part of wayland on some distros)
+- wayland-protocols
+- Qt6 [ QtWayland ]
+
+### Building
+
+To make a release build of quickshell run:
+```sh
+$ just release
+```
+
+If you have all the dependencies installed and they are in expected
+locations this will build correctly.
+
+To install to /usr/local/bin run as root (usually `sudo`) in the same folder:
+```
+$ just install
+```
+
+### Building (Nix)
+
+You can build directly using the provided nix flake or nix package.
+```
+nix build
+nix build -f package.nix # calls default.nix with a basic callPackage expression
+```
+
+# Development
+
+For nix there is a devshell available from `shell.nix` and as a devShell
+output from the flake.
+
+The Justfile contains various useful aliases:
+- `just configure [<debug|release> [extra cmake args]]`
+- `just build` (runs configure for debug mode)
+- `just run [args]`
+- `just clean`
+- `just test [args]` (configure with `-DBUILD_TESTING=ON` first)
+- `just fmt`
+- `just lint`
+
 #### License
 
 <sup>