Add deno to contributing.md (#1389)

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>

Author: ehaca

.hyperlint/config.yaml

@@ -0,0 +1,3 @@
+reviewer:
+  external_link_validation:
+    ignore_url_keywords: ["deno"]

docs/contributing.md

@@ -9,17 +9,24 @@ git clone git@github.com:<your username>/pydantic-ai.git
 cd pydantic-ai
 ```
 
-Install `uv` (version 0.4.30 or later) and `pre-commit`
-
-We use pipx here, for other options see:
+Install `uv` (version 0.4.30 or later), `pre-commit` and `deno`:
 
 * [`uv` install docs](https://docs.astral.sh/uv/getting-started/installation/)
 * [`pre-commit` install docs](https://pre-commit.com/#install)
+* [`deno` install docs](https://docs.deno.com/runtime/getting_started/installation/)
+
+To install `pre-commit` you can run the following command:
+
+```bash
+uv tool install pre-commit
+```
 
-To get `pipx` itself, see [these docs](https://pypa.github.io/pipx/)
+For `deno`, you can run the following, or check
+[their documentation](https://docs.deno.com/runtime/getting_started/installation/) for alternative
+installation methods:
 
 ```bash
-pipx install uv pre-commit
+curl -fsSL https://deno.land/install.sh | sh
 ```
 
 Install `pydantic-ai`, all dependencies and pre-commit hooks