Pages 375 and 400 - navigation in source

[rmantel23]

Since the option is called 'Enable navigation to Source' it would probably be better to instruct the reader to search for that (to instead of in), so it highlights the option.

[markjprice]

Thanks. I've added errata items for these:
https://github.com/markjprice/cs12dotnet8/blob/main/docs/errata/errata.md#page-375---revealing-the-location-of-a-type