Make it clearer that the embedded browser preview in the VS Code DevTools extension is only a simple preview with many restrictions

[captainbrosset]

Link to the documentation page: https://learn.microsoft.com/en-us/microsoft-edge/visual-studio-code/microsoft-edge-devtools-extension/external-browser-window

Description of the issue: We keep getting issues on the https://github.com/microsoft/vscode-edge-devtools/ repo from people realizing that the embedded browser doesn't support all web features. One of the most recent is the lack of drag&drop support: microsoft/vscode-edge-devtools#2030 but there are other instances of this:

• onPasteCapture onPaste events wont trigger on this browser. microsoft/vscode-edge-devtools#2006
• css cursor property is not being respected its always default sad :( microsoft/vscode-edge-devtools#1996
• Cursor Pointer Issue microsoft/vscode-edge-devtools#1656
• A missing CSS feature microsoft/vscode-edge-devtools#2084
• Please add support for cursor: pointer microsoft/vscode-edge-devtools#2149

We should document the fact that the embedded browser is based on a headless browser instance from which screen captures are being streamed and that, therefore, not all user interactions are implemented. Also, that visual performance issues might exist.
We should then tell users that, if these unsupported features are important to them, they should use an external browser window.

AB#49097200