minor copyedits, add caution re server-side node

Author: mmrj

README.md

@@ -1,7 +1,22 @@
-### LaunchDarkly Sample TypeScript Node.js Application ###
-We've built a simple console application that demonstrates how LaunchDarkly's SDK works. Below, you'll find the basic build procedure, but for more comprehensive instructions, you can visit your [Quickstart page](https://app.launchdarkly.com/quickstart#/).
+# LaunchDarkly sample TypeScript Node.js (server-side) application
+
+We've built a simple console application that demonstrates how LaunchDarkly's SDK works.
+
+
Below, you'll find the build procedure. For more comprehensive instructions, you can visit your [Quickstart page](https://app.launchdarkly.com/quickstart#/) or the [Node.js (server-side) reference guide](https://docs.launchdarkly.com/sdk/server-side/node-js).
+
+The LaunchDarkly server-side SDK for Node.js is designed primarily for use in multi-user systems such as web servers and applications. It follows the server-side LaunchDarkly model for multi-user contexts. It is not intended for use in desktop and embedded systems applications.
+
+For a sample application demonstrating how to use LaunchDarkly in *client-side* Node.js applications, refer to our [Client-side Node.js SDK sample application](https://github.com/launchdarkly/hello-node-client).
+
+## Build instructions
 
-##### Build instructions #####
 1. Install the LaunchDarkly Node.js SDK by running `npm install`
-2. Copy your API key and feature flag key from your LaunchDarkly dashboard into `index.ts`
-3. Run `npm start`
+2. Edit `index.ts` and set the value of `sdkKey` to your LaunchDarkly SDK key. If there is an existing boolean feature flag in your LaunchDarkly project that you want to evaluate, set `featureFlagKey` to the flag key.
+
+```js
+  const sdkKey = "1234567890abcdef";
+
+  const featureFlagKey = "my-flag";
+```
+
+3. Run `npm start`