Added README

Author: kolloch

README.md

@@ -0,0 +1,36 @@
+# tracing-tree
+
+Instrument your application with [tracing](https://github.com/tokio-rs/tracing)
+and get tree-structured summaries of your application activity with timing
+information on the console:
+
+<pre> 
+ <b>server</b>{host=&quot;localhost&quot;, port=8080<b>}</b>
+    0ms <b> INFO</b> starting
+    300ms <b> INFO</b> listening
+    <b>conn</b>{peer_addr=&quot;82.9.9.9&quot;, port=42381<b>}</b>
+      0ms <b>DEBUG</b> connected
+      300ms <b>DEBUG</b> message received, length=2
+    <b>conn</b>{peer_addr=&quot;8.8.8.8&quot;, port=18230<b>}</b>
+      300ms <b>DEBUG</b> connected
+    <b>conn</b>{peer_addr=&quot;82.9.9.9&quot;, port=42381<b>}</b>
+      600ms <b> WARN</b> weak encryption requested, algo=&quot;xor&quot;
+      901ms <b>DEBUG</b> response sent, length=8
+      901ms <b>DEBUG</b> disconnected
+    <b>conn</b>{peer_addr=&quot;8.8.8.8&quot;, port=18230<b>}</b>
+      600ms <b>DEBUG</b> message received, length=5
+      901ms <b>DEBUG</b> response sent, length=8
+      901ms <b>DEBUG</b> disconnected
+    1502ms <b> WARN</b> internal error
+    1502ms <b> INFO</b> exit
+</pre>
+
+## Setup
+
+After instrumenting your app with
+[tracing](https://github.com/tokio-rs/tracing), add this subscriber like this:
+
+```
+    let subscriber = Registry::default().with(HierarchicalLayer::new(2));
+    tracing::subscriber::set_global_default(subscriber).unwrap();
+```