docs: Improve mention of cmd:skip-release-notes label

The label is automatically created in the `frequenz-floss` organization,
so it is not necessary to create it manually. But when used to create
repos in another organization, it might be, so we need to still
explaining how to create it.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

docs/user-guide/start-a-new-project/github-configuration.md

@@ -12,12 +12,11 @@ Review the list of labels and add:
 
 * `part:xxx` labels that make sense to the project
 
-* Add a `cmd:skip-release-notes` with the following description:
+* Make sure there is a `cmd:skip-release-notes` label, and if there isn't,
+  create one with `930F79` as color and the following description:
 
     > It is not necessary to update release notes for this PR
 
-    And `930F79` as color.
-
 * All labels used by automation in the project, for example look for labels listed in:
 
     * `.github/keylabeler.yml`