add links to buildx description (#573)

* add links to buildx description

Author: daniel-codefresh

graduated/build/step.yaml

@@ -8,7 +8,7 @@ metadata:
   sources:
     - 'https://github.com/codefresh-io/steps/tree/master/graduated/build'
   stage: graduated
-  version: 1.2.0
+  version: 1.2.1
   categories:
     - featured
     - docker
@@ -193,7 +193,7 @@ spec:
                       "additionalProperties": false
                   }
                 ],
-                "description": "Build and push Docker images with Buildx including multi-platform builds (set to `true` to enable with default configuration, or set to an object with custom configuration).",
+                "description": "Build and push Docker images with <a href=\"https://github.com/docker/buildx\">Buildx</a> including multi-platform builds (set to `true` to enable with default configuration, or set to an object with custom configuration). <a href=\"https://codefresh.io/docs/docs/pipelines/steps/build/#multi-platform-images-with-platfrom-and-buildx\">more info</a>",
                 "default": false
             },
         }