PSTeams is a PowerShell Module working on Windows / Linux and Mac. It allows sending notifications to Microsoft Teams via WebHook Notifications. It's pretty flexible and provides a bunch of options. Initially, it only supported one sort of Team Cards but since version 2.X.X it supports Adaptive Cards, Hero Cards, List Cards, and Thumbnail Cards. All those new cards have their own cmdlets and the old version of creating Teams Cards stays as-is for compatibility reasons.
Samples on different adaptive card designs demonstrating the art of possible with them. Designs provided by the Microsoft design team and first versions targeting Viva Connections Adaptive Card Extensions (ACE) scenarios.
Visual Studio Code Extension to help create AdaptiveCards. The extension not only allows you to see the card you're working on but also comes with nice snippets and helpfull utilities.
Would be great if the designer could be installed as a PWA