Placeholders when creating publications

**Is your feature request related to a problem? Please describe.**

Can we add guidance around what things can have a placeholder when creating a publication for a team? For example, titles and summaries for publications? We can also set hard deadlines for when those placeholders need to be replaced with the real things.

**Describe the solution you'd like**
Maybe add it to the [requesting a new publication section](https://dfe-analytical-services.github.io/analysts-guide/statistics-production/ees.html#requesting-a-new-publication) under a subheading for sensitive publications? Also add considerations around not having approvers on until things are finalised.