Add deno example

Author: petyosi

README.md

@@ -195,6 +195,12 @@ The `logfire.configure` call should happen before the actual express module impo
 },
 ```
 
+## Deno
+
+Deno has [built-in support for OpenTelemetry](https://docs.deno.com/runtime/fundamentals/open_telemetry/). The examples directory includes a `Hello world` example that configures Deno OTel export to Logfire through environment variables.
+
+Optionally, you can use the Logfire API package for creating manual spans. Install the `@pydantic/logfire-api` NPM package and call the respective methods from your code.
+
 #### Configuring the instrumentation
 
 The `logfire.configure` function accepts a set of configuration options that control the behavior of the instrumentation. Alternatively, you can [use environment variables](https://logfire.pydantic.dev/docs/reference/configuration/#programmatically-via-configure) to configure the instrumentation.

examples/deno-project/deno.json

@@ -0,0 +1,8 @@
+{
+  "tasks": {
+    "dev": "deno run --allow-net main.ts"
+  },
+  "imports": {
+    "@std/assert": "jsr:@std/assert@1"
+  }
+}

examples/deno-project/main.ts

@@ -0,0 +1,3 @@
+Deno.serve({ port: 4242 }, (_req) => {
+  return new Response("Hello, World!");
+});

examples/deno-project/start.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env sh
+OTEL_DENO=true \
+  OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=https://logfire-api.pydantic.dev/v1/traces \
+  OTEL_EXPORTER_OTLP_HEADERS='Authorization=your-token' \
+  deno run --unstable-otel --allow-net main.ts