Unclear where to add explanatory text

[tmtmtmtm]

Now that I have set up https://www.wikidata.org/wiki/User:Oravrattas/prompts/Riigikogu, I want to add introductory text for visitors to the page to explain what it is, how to fix things, etc. as well as some notes beside the comparison table about any expected differences etc.

It's unclear how/where I actually do things like this.

[lucychambers]

Clarification: the documentation for how to use each individual prompt might be different but currently it is not clear how to add custom documentation to a prompt.