docs(guides): add an Expo guide

docs/docs/guides/with-expo.md

@@ -0,0 +1,48 @@
+---
+sidebar_position: 4
+---
+
+# Developing with Expo
+
+Expo is a popular development platform in the react-native ecosystem.
+
+## Custom Entrypoint
+
+By default, Expo points to an entrypoint in the `node_modules` package. The path for this is configured in the `"main"` field of `package.json`. To configure the Playback Service in this entrypoint file:
+
+1. Copy the file
+
+```
+cp node_modules/expo/AppEntry.js AppEntry.js 
+```
+
+2. Update the `"main"` field of `package.json` to the new location e.g. `"AppEntry.js"`
+3. Edit the file to have it import your app code, and configure the Playback Service.
+
+
+## Streaming HTTP
+
+On newer versions of Android, HTTP streaming is disallowed by default (HTTPS is OK). However, it is only disallowed in production builds which can make this issue hard to diagnose.
+
+To allow HTTP, you must first install the [`expo-build-properties` package](https://docs.expo.dev/versions/latest/sdk/build-properties).
+
+```
+expo install expo-build-properties
+```
+
+Then add this configuration in `app.json`:
+
+```json
+...
+    "plugins": [
+      [
+        "expo-build-properties",
+        {
+          "android": {
+            "usesCleartextTraffic": true
+          }
+        }
+      ]
+    ]
+...
+```