Add default styles and templates for the bar

- [ ] Copy a `Resources.xaml` template to the user's `.whim` folder when installing
- [ ] Add a commented `code snippet` in the `whim.config.csx` to load the template
- [ ] Revisit the design of the default style
- [ ] Package additional default styles to choose from?
- [ ] What should be the height of the bar? Monitor scaling might interfere with this, see https://github.com/dalyIsaac/Whim/pull/723#discussion_r1431029615 and https://github.com/dalyIsaac/Whim/pull/723#discussion_r1429284791

Start by reviewing the Resources.xaml template, the user's .whim installation flow, and whim.config.csx, then read the linked pull request discussions about bar height and scaling. The issue is done only after the default template and commented loading snippet are defined, the default style and optional styles are decided, and installation behavior is implemented.

Written by the indexing model from the issue text.