Update readme with more information on sharing URLs

README.md

@@ -9,6 +9,22 @@ The playground is a [Svelte](https://svelte.dev) app which uses the
 [WebAssembly build of MiniZinc](https://github.com/minizinc/minizinc-js) to run MiniZinc locally in the browser.
 The GUI is styled using [Bulma](https://bulma.io) and [CodeMirror](https://codemirror.net) is used for the code editor.
 
+## Sharing projects
+
+The playground supports generating a link which opens the active project (including the current tab and solver settings) using the share button on the top-right. It may be useful to pass these through a link shortening service to get more friendly URLs.
+
+### Loading code directly
+
+You can also generate URLs which directly populate the playground with some code by using `#code=<minizinc code>` as the URL hash.
+
+For example: [`https://play.minizinc.dev/#code=var%201..3%3A%20x%3B`](https://play.minizinc.dev/#code=var%201..3%3A%20x%3B)
+
+### Loading from a remote source
+
+It's also possible to generate a link to load a project from a remote URL by using `#url=<file url>` as the hash.
+
+For example: [`https://play.minizinc.dev/#url=https%3A%2F%2Fraw.githubusercontent.com%2FMiniZinc%2Flibminizinc%2Fmaster%2Fdocs%2Fen%2Fexamples%2Floan%2Floan.mzp`](https://play.minizinc.dev/#url=https%3A%2F%2Fraw.githubusercontent.com%2FMiniZinc%2Flibminizinc%2Fmaster%2Fdocs%2Fen%2Fexamples%2Floan%2Floan.mzp)
+
 ## Development
 
 ```sh