Improve readme for embedded router. (#936)

* Improve readme for embedded router.

Co-authored-by: Coenen Benjamin <benjamin.coenen@hotmail.com>

Co-authored-by: bryn <bryn@apollographql.com>
Co-authored-by: Coenen Benjamin <benjamin.coenen@hotmail.com>

NEXT_CHANGELOG.md

@@ -112,5 +112,9 @@ Minor simplification of code to remove boxing during instrumentation.
 ## 📚 Documentation
 ### Enhanced rust docs ([PR #819](https://github.com/apollographql/router/pull/819))
 Many more rust docs have been added.
+
 ### Federation version support page [PR #896](https://github.com/apollographql/router/pull/896)
-Add Federation version support doc page detailing which versions of federation are compiled against versions of the router. 
+Add Federation version support doc page detailing which versions of federation are compiled against versions of the router.
+
+### Improve readme for embedded Router [PR #936](https://github.com/apollographql/router/pull/936)
+Add more details about pros and cons so that users know what they're letting themselves in for.  

examples/embedded/README.md

@@ -2,13 +2,19 @@
 
 :exclamation: Here be dragons! :exclamation: 
 
-It is possible to run the router outside the default bundled web server (Warp). Reasons to do this are:
+It is possible to run the router outside the default bundled web server (Axum). 
 
-* You have an existing web server stack that you wish to integrate with.
-* You have very high performance requirements and you want to avoid the hit of dynamic configuration.  
-* You have particular configuration management requirements that are not currently catered for.
-* You have something highly custom that you want to do.
+## Reasons to avoid this
+
+* Router APIs are not stable. You will effectively be making a fork of the Router.
+* You will lose hot-reload, telemetry, configuration and Apollo Studio support.
+* Managing lifecycle is hard, re-creating a good configuration and validation experience will be lots of work.
+* We will be looking at increasing the capability of the plugin system over time.
+* We will be looking to support multiple deployment platforms over time.
 
-We don't have a compatibility matrix between the router and other libraries, so do expect incompatibilities.
+## Reasons to consider this
 
+* You have an existing web server stack that you wish to integrate with.
+* You have particular configuration management requirements that are not currently catered for.
+* You have something highly custom that you want to do and are prepared to go it alone.