added echo server to tools

documentation/docs/pages/developers/tools/_meta.json

@@ -1,5 +1,4 @@
 {
-  "nym-cli": "NYM-CLI tool",
-  "cli-wallet": "CLI wallet",
+  "nym-cli": "Nym-cli",
   "echo-server": "Echo Server"
 }

documentation/docs/pages/developers/tools/echo-server.mdx

@@ -0,0 +1,16 @@
+# Echo Server
+
+There is an initial version of a simple echo server located at [`nym/tools/echo-server`](https://github.com/nymtech/nym/tree/develop/tools/echo-server).
+
+This is an initial minimal implementation of an echo server built using the [`NymProxyServer`](../rust/tcpproxy) Rust SDK abstraction that, aside from the initialisation and running of a `NymProxyServer` instance in the background, is essentially a vanilla TCP echo server written with `tokio`.
+
+You can find usage commands [here](https://github.com/nymtech/nym/tree/develop/tools/echo-server#usage).
+
+This server was initially built for the `TcpProxy` tests, but can be useful for developers to need a constant endpoint to ping when developing. In the future this will be deployed to a remote server so developers don't have to run their own.
+
+## Logging
+Every 10 seconds, the server logs:
+- the total number of bytes received since startup
+- the total number of bytes sent since startup
+- the current number of concurrent connections it has
+- the total number of concurrent connections it has