Broken link in 'What's new in C# 7.0 thru C# 7.3 - exploration'

[calumtomeny]

Reproduction steps

1. Navigate to the folder: try-samples\csharp7
2. Run the command dotnet try
3. Click on the link to 'ref struct'

Actual result: receive the error 'This localhost page can’t be found' Expected result: the 'readonly-struct.md' page should load and should scroll to the relevant section

Notes: The URL contains '/readonly-struct#ref-struct-types.md' and it should be /readonly-struct.md#ref-struct-types.