## Launch Checklist
- [x] Briefly describe the changes in this PR.
* When adding a new Raster or Raster-dem tile source, use `.png` as the
hint for the tile URL hint prompt.
* Currently, the user is prompted for a Vector tile source (e.g.,
`.pbf`)
* If a new Mapnik user already has their XYZ raster Tile URL, then they
may already know how to modify this text field.
* This change may be useful for new users and is intended for them.
* `.png` is a start. It could be `.webp` or `.jpg`, or `.jpg`, or in the
case of Esri there is no extension for the images.
* See [RobLabs.com/xyz](https://RobLabs.com/xyz) for sample XYZ raster
tile URLs
---
- [x] Include before/after visuals or gifs if this PR includes visual
changes.
* Steps to reproduce
* See [RobLabs.com/maputnik](https://roblabs.com/maputnik) for a working
version of this fix for Maputnik
* On top menu bar: *Data Sources* > In the *Add New Source* section >
Change *Source Type* to "Raster (Tile URLs)"
* There you will see prompt hint for a raster Tile instead of vector
tile `.pbf`.
* See the release notes for the National Park Service prototype release
for [Maputnik for National Park Service Park
Tiles](https://github.com/roblabs/maputnik/releases/tag/v2.1.1-nationalparkservice)
for more screen shots.
#### Before
`.pbf` may be confusing for those adding a Raster
#### After
---
- [x] Write tests for all new functionality.
* See screen shots for functionality
- ~~[] Add an entry to `CHANGELOG.md` under the `## main` section.~~
*Not really a feature, so I will leave this out*
- [ ] ~~Link to related issues.~~
