wrong url of Legacy C# Support extension in VSCode's introduction view with Mac OS X.

[sassembla]

correct Legacy C# Support extension url is below.
https://marketplace.visualstudio.com/items?itemName=ms-vscode.omnisharp

but current target url is below.(goes to wrong empty page of marketplace.)
https://marketplace.visualstudio.com/items?itemName%3Dms-vscode.omnisharp

[sassembla]

Oops, Close button has been pressed by my mistake.

[DustinCampbell]

Thanks @sassembla! Apologies for the error!

[DustinCampbell]

This should go away with this release. We're removing the need for the Legacy C# Support extension in 1.3

[DustinCampbell]

This has been removed from our readme.md. Once we ship the latest extension (1.3.0) to the marketplace, this will be reflected there as well.