Updating README with API initialisation and tips.

README.md

@@ -0,0 +1,26 @@
+# Installation
+
+## Launch API
+`go run ./cmd/api`
+
+If you want, you can also verify that the command-line flags are working correctly by specifying alternative **port** and **env** values when starting the application.  
+When you do this, you should see the contents of the log message change accordingly. For example :
+
+`go run ./cmd/api -port=3030 -env=production`  
+**time=2025-10-10T11:08:00.000+02:00 level=INFO msg=
+"starting server" addr=:3030 env=production**
+
+## Test endpoints
+`curl -i localhost:4000/v1/healthcheck`  
+The *-i* flag in the command above instructs curl to display the HTTP response headers as well as the response body.
+
+### Result  
+
+HTTP/1.1 200 OK  
+Date: Mon, 05 Apr 2021 17:46:14 GMT  
+Content-Length: 58  
+Content-Type: text/plain; charset=utf-8  
+
+status: available  
+environment: development  
+version: 1.0.0