Move CI doc page under contributor guide
* xref:contributor-guide.adoc[Contributor guide]
** xref:create-new-extension.adoc[Create new extension].
** xref:promote-jvm-to-native.adoc[Promote JVM extension to Native].
+** xref:ci.adoc[Camel Quarkus Continuous Integration Builds]
* xref:list-of-camel-quarkus-extensions.adoc[List of Camel Quarkus extensions]
-* xref:ci.adoc[Camel Quarkus Continuous Integration Builds]
