This is a development build of the Azure Quantum Development Kit, and is intended for early testing of upcoming features.
To install the tested version of this extension, visit https://marketplace.visualstudio.com/items?itemName=quantum.qsharp-lang-vscode. The README for the stable build contains details on features and usage.
For more information about the Modern QDK and Azure Quantum, visit https://aka.ms/AQ/Documentation.