Say how dotnet run listens, and what to do about a second solution file #90

Two docs fixes from trying the templates by hand:

• dotnet run redirects http://localhost:8080 to https://localhost:8081, so a plain curl got an empty 307. RUN.md and the site now use the HTTPS address and say how to trust the development certificate. The redirect itself stays.

• Visual Studio and Rider can write a second solution file. The getting-started pages say to pick .slnx and keep it.

• Say that dotnet run redirects HTTP to HTTPS CleanMinimalApi#81

• Say that dotnet run redirects HTTP to HTTPS CleanModelContextProtocol#61

• Say that dotnet run redirects HTTP to HTTPS CleanGraphQLApi#61

• Say that dotnet run redirects HTTP to HTTPS CleanWebApi#55

• Say what to do when the IDE makes a second solution file leanmeancleanapps.github.io#20

• Bring the docs up to date with review text, review search and the new MCP features leanmeancleanapps.github.io#21

Filed after the work merged on 7 November, so the board shows it in the 1 December release.