Update templated README.md file

Author: anitarua

example/README.md

@@ -12,6 +12,7 @@ This directory contains fully-functioning examples that demonstrate how to use t
 
 - Follow the [installation guide](https://doc.rust-lang.org/cargo/getting-started/installation.html) to install Rust and Cargo.
 - To get started with Momento you will need a Momento API key. You can get one from the [Momento Console](https://console.gomomento.com).
+- A Momento service endpoint is required. You can find a [list of them here](https://docs.momentohq.com/platform/regions)
 
 Here are the different examples available: