[IA] Rename site section paths to `dotnet` from `net`

[chalin]

There is an inconsistency in the site URL paths used for .Net sections relative to other languages. We're currently using net in these two places:

• /docs/languages/net, which is published as https://opentelemetry.io/docs/languages/net/
• /docs/zero-code/net

The path name "net" seems wrong. Besides, we use dotnet as our language ID internally, and that would also make more sense as a site URL path segment name.

I'd propose that we change it to dotnet. This will simplify some of our internal code that needs to single-out the exception and special-case it at the moment, and make the site URL paths more intuitive.

Thoughts @svrnm @open-telemetry/docs-approvers @open-telemetry/dotnet-approvers? If we do make the change, we'll use direct rules to ensure that the old URLs (using net) continue to work.

Tasks

• [IA] Rename net to dotnet in /docs/{languages,zero-code}/net, add redirects and adjust links #6590
  • Rename the paths under content of /docs/languages/net and /docs/zero-code/net to use dotnet instead of net
  • Add appropriate redirects
  • Fix the registry too
• Adjust any shortcodes and/or includes, e.g., layouts/shortcodes/docs/languages/exporters/intro.md and it's associated include.

[svrnm]

I am in favor of this change. Especially with redirects we can have both 👍

[theletterf]

Agree with going for dotnet, it's more idiomatic to the .NET ecosystem.

[tiffany76]

I agree. dotnet is better.

[Kielek]

I am fine with dotnet as long as we have redirectins in place.

[chalin]

Note that we'll also need to adjust the registry code, since it was coded with net. I'll add this subtask to the opening comment too.