[Examples] updated styled-components

[falsepopsky]

Example

• added declaration file types for the used theme Create a declarations file
• added custom styled component that wraps an <a> tag like the next js docs as example Next link DOCS
• changed the ui page like the create-next-app examples

Dependencies

• updated deps to latest
• added types for SC => @types/styled-components
• removed react-is, unused in this example

Example deploy

Documentation / Examples

• Make sure the linting passes by running pnpm lint
• The examples guidelines are followed from our contributing doc

[balazsorban44]

Thanks!