Remind about installation when using programmatically

README.md

@@ -17,7 +17,7 @@ A small utility (and CLI) to import content files from various content sources.
 
 ## Usage
 
-Published to [npm](https://www.npmjs.com/package/@11ty/import).
+Published to [npm](https://www.npmjs.com/package/@11ty/import). These commands do not require separate installation.
 
 ```sh
 npx @11ty/import --help
@@ -107,6 +107,8 @@ npx @11ty/import bluesky @11ty.dev
 
 ### Programmatic API
 
+Don’t forget to install this into your project: `npm install @11ty/import`
+
 ```js
 import { Importer } from "@11ty/import";