README: Document available recipes

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>

README.md

@@ -4,3 +4,27 @@ This repository contains Apertis recipes customized for Raspberry Pi.
 
 Based on [Apertis Image Recipes](https://gitlab.apertis.org/infrastructure/apertis-image-recipes/)
 official repository. Check it out for further documentation on Apertis recipes.
+
+## Available recipes
+
+### ospack-minimal.yaml
+
+Build platform-independent minimal (headless system) ospack.
+
+Based on [Apertis Image Recipes](https://gitlab.apertis.org/infrastructure/apertis-image-recipes/)
+`ospack-minimal.yaml` original recipe.
+
+Includes extra tools for development purposes, docker engine and docker-compose.
+
+```
+debos --scratchsize=10G ospack-minimal.yaml
+```
+
+### image-rpi64.yaml
+
+Build platform-specific image for Raspberry Pi using a previously built ospack
+(minimal by default).
+
+```
+debos --scratchsize=10G image-rpi64.yaml
+```