Move to OTP 27 locally and add run instructions

.tool-versions

@@ -1,2 +1,2 @@
 # also update ci.yml
-erlang 26.2.5.2
+erlang 27.1.1

README.md

@@ -2,17 +2,18 @@
 
 This app provides an HTTP API for gathering and querying metrics from an erldns server and presenting those metrics as JSON.
 
-Here's an example script that shows how to get the output with curl and pass through Python to format it in a pretty fashion.
+Here's an example script that shows how to get the output with `curl` and pass it through Python to format it in a pretty fashion. It assumes you have this API running on port `8082`.
 
 ```bash
 curl -s http://localhost:8082/ -H "Accept: application/json" | python -mjson.tool
 ```
 
-Note that timing stats are givin in microseconds.
+> [!IMPORTANT]
+> Timing stats are given in microseconds.
 
 ## Configuration
 
-To configure the metrics API port, add something like the following to your erlang configuration section:
+To configure the metrics API port, add something like the following to your Erlang configuration section:
 
 ```erlang
 [
@@ -37,3 +38,42 @@ To start fresh:
 ```bash
 make fresh
 ```
+
+## Running
+
+You'll need [erldns]() running. Then, you can run erldns_metrics as:
+
+```bash
+rebar3 shell
+```
+
+If you need to configure erldns (such as to use a different port), you can store configuration such as the one below in a file such as `erldns_metrics.config`:
+
+```erlang
+[
+    {erldns, [
+        {servers, [
+            [
+                {name, inet_localhost_1},
+                {address, "127.0.0.1"},
+                {port, 8053},
+                {family, inet},
+                {processes, 2}
+            ],
+            [{name, inet6_localhost_1}, {address, "::1"}, {port, 8053}, {family, inet6}]
+        ]}
+    ]}
+].
+```
+
+Then, you can run erldns_metrics as:
+
+```bash
+rebar3 shell --config erldns_metrics.config
+```
+
+## Testing
+
+```bash
+make test
+```

rebar.config

@@ -29,3 +29,6 @@
    {warnings, [no_unknown]}
 ]}.
 
+{shell, [
+   {apps, [erldns_metrics]}
+]}.