Note: we do not tag patch releases of NodeJS, only minor versions. You will find for example an image for NodeJS 6.x, but no tagged image for NodeJS 6.0.1. This is because we believe you have no valid reason to ask explicitly for 6.0.1. When 6.0.2 is out, you certainly want to upgrade automatically to this patch release since patch releases contain only bugfixes.
But there are only major versions, no minor versions of node (which is ok in my opinion)
Maybe adapt the README to:
Note: we do not tag minor releases of NodeJS, only major versions. You will find for example an image for NodeJS 6.x, but no tagged image for NodeJS 6.9. This is because NodeJS follows SemVer and we believe you have no valid reason to ask explicitly for 6.1. When 6.2 is out, you certainly want to upgrade automatically to this minor release since it is backward compatible.
Readme says:
But there are only major versions, no minor versions of node (which is ok in my opinion)
Maybe adapt the README to: