**Requirements**
[] Implement behind feature flag
[x] Add a new parameter property to TemplateData, called 'suggestedvalues' in JSON. //Note: on test instance this was titled datalist. We want to make sure that the naming is consistent in the final implementation.//
[] Add field to edit this new property in the TemplateData editor on the parameter properties page underneath the type property.
[x] Give this field a label of: "Suggested values"
[] Only have this property visible when the following parameter types are selected: Content, Line, String, Unknown, Number, File, Page, Template. Otherwise, hide the property and its field.
[] Placeholder text: "Add value..."
[] For input, use OOUI TagMultiselectWidget (allowArbitrary, inline input, placeholder). The items can then also include commas.
[] When rendering the embedded TemplateData table in an article, display the suggested values under a bold heading beneath the description, as is done for `default` and `example`.
**Mock**
{F34111807}
Relevant prototype commits:
* https://gitlab.com/wmde/mediawiki-extensions-TemplateData/-/commit/682a2552b3df4a315f2e7ab81fe34a093f3525cd