improve sourcepawn script documentation

README.md

@@ -11,6 +11,8 @@ The following is currently packaged:
 - `metamod-source`
 - `sourcemod`
 - [`sourcemod-include-library`](https://github.com/JoinedSenses/SourceMod-IncludeLibrary)
+- [`sourcemod-include-curl`](https://github.com/sapphonie/SM-neocurl-ext)
+- `sourcemod-include-steamworks`
 - `srcds-tf2`
 
 ## TF2 Dedicated server
@@ -75,9 +77,23 @@ buildSourcePawnScript {
 By default, the sourcemod includes are available.
 
 Additional includes can be added by setting the `includes` argument to an array
-of packages containing an `include` folder containing the `.inc` files. A helper
+of packages containing an `include` folder containing the `.inc` files. This
-is provided to create include packages:
+flake packages a number of common includes and a helper is provided to create
+include packages:
 
 ```nix
 sourcepawn.buildInclude [./cURL.inc ./cURL_header.inc]
 ```
+
+```nix
+buildSourcePawnScript {
+  name = "test";
+  src = ./test.sp;
+  includes = [
+    pkgs.sourcemod-include-curl
+    (
+      sourcepawn.buildInclude [./custom.inc]
+    )
+  ];
+};
+```