Separate demos into mobile-only, desktop-only and mobile and desktop compatible

[Maceeran]

Description

• Separated example link list into mobile-only, desktop-only and mobile and desktop compatible lists
• Added mobile-only/desktop-only information into individual example pages where applicable
• Standardized demo description styling(set class to "text-muted")

Checklist

Changes to the drivers

• (PR Author) The affected drivers were manually tested

Changes to CLI

• (PR Author) The change was manually tested with the CLI
• (PR Author) The affected CLI features are working with the standalone binary (at least one platform)
• (Checked by maintainer) The CLI test procedure was run by the project's maintainer

Changes to web library

• (PR Author) The change was manually tested with the web library included within a classic HTML application (flat libhalo.js)
• (PR Author) The change was manually tested with the web library included within an app based on frontend framework (React.js or similar based on webpack)
• (Checked by maintainer) The web test suite was run by the project's maintainer

Changes to nfc-manager driver

• (PR Author) The change was manually tested in React Native app
• (Checked by maintainer) The test suite was run through the test React Native project