[pfe-tools]: wrong docsTemplatePath generated for elements in custom elements manifest plugin

[eyevana]

The plugin is generating the wrong docsTemplatePath for the elements in my cpelements project. I'm not able to pull the templates to generate the docs for my components. Here's the patch @bennypowers: https://gitlab.cee.redhat.com/customer-platform/cp-elements/-/commit/4a187c130350a12a372d6c751953023df3d9e77a#a2f13cc857fd094a668d30a7d5eb1b2e91cef5bc