Better typed function to generate media queries

I believe the isn’t a TypeScript issue but rather an IntelliSense plugin issue.

From the perspective of TypeScript, the content between the backticks is of type TemplateStringsArray. TypeScript isn’t aware of valid CSS properties as it sees an array of strings.

I believe the validation is done at the plugin level by typescript-styled-plugin.

See https://github.com/styled-components/vscode-styled-components/pull/41

I would submit a feature request or bug report here.