Problem:
When using a plugin for YAML syntax support for VSCode editor developed by Red Hat, it does not enable the auto-completion feature for Kubernetes manifest files by default. As an auto-completion feature, it offers to use the CTRL + Space shortcut key. But this may not be a good option to choose, as the plugin has automatic syntax completion for Kubernetes manifest files during typing without using a shortcut key.

Solution:

1. Install the plugin in VSCode from here.
2. On the plugin page click on the gear button and select Extension Settings
   
3. Scroll down and in YAML: Schemas select Edit in settings.json:
   
4. In settings add the following code and save the changes:

    "yaml.schemas": {
        "kubernetes": "*.yaml"
    }
   

5. Restart VSCode.
6. Enjoy auto-completion for Kubernetes manifest files!