chore(docs): getting started

Author: leocavalcante

README.md

@@ -2,4 +2,18 @@
 
 🔭 Drop-in replacement for the `hyperf/metric` component.
 
-Suited for special needs.
+Suited for special needs, especially for OpenTelemetry, New Relic and Dynatrace platforms.
+
+## Getting started
+
+### Install
+
+#### Add OpenCodeCo's Composer repository:
+```shell
+composer config repositories.opencodeco composer https://composer.opencodeco.dev
+```
+
+#### Update your `hyperf/metric`:
+```shell
+composer update hyperf/metric
+```