Should we provide configuration for required tiling parameters?

There are query parameters that tiling backends expect or accept but which aren’t specified in the collection document. In the example collections so far, we have `datetime`, `variable` or `collection_concept_id`.

There is no way for a client to tell, which of these parameters need to be passed to the tiler in addition to those specified in the render extension. For example, `datetime` can be a single date or a range, depending on the tiler. `variable` and `concept_id` are only required for titiler-cmr implementations but not for titiler-pgstac.

Should these parameters be advertised the render extension? There could be an addition block called `parameters` that indicates what parameters the tile expects and accepts in addition to those defined in the each render object.

```json
{
"renders": {
"parameters": {
"variable": {
"type": "string",
"required": true
},
"concept_id": {
"type": "string",
"required": true
},
"datetime": {
"type": "datetime",
"required": true,
"extent": "range"
}
}
}
}
```

Likewise, if these parameters are tiler-specific, should the tiler endpoint be advertised in the render extension as well?