Create documentation that describes how to troubleshoot and fix `'0 functions loaded'` for a dotnet and a dotnet-isolated app

We do not have any public documentation that describes how to fix this issue.

Below is an answer on how to fix this issue from ChatGPT. Could you please verify this information and add anything that might be missing? Also, if the troubleshooting instructions are different for `dotnet` and `dotnet-isolated`, please create a section for each.

**ChatGPT Answer**:
If you're encountering the `"0 functions loaded"` issue for your .NET Azure Function, it means that the Azure Functions runtime was unable to discover and load any functions within your project. This issue can have several causes, and I'll outline some steps to troubleshoot and resolve it:

1. **Check Your Function Code**:
- Ensure that you have one or more functions defined in your project. Functions should be defined as methods with appropriate attributes (e.g., `[FunctionName]`) to identify them as Azure Functions.

2. **Function Names and Signatures**:
- Confirm that your function methods have the correct names and signatures. The `[FunctionName]` attribute should match the function name you expect to trigger.

3. **Function Project Structure**:
- Verify that your project has the correct structure for Azure Functions. It should include a `csproj` file and a folder structure that follows the convention (e.g., `MyFunctionProject/FunctionName.cs`).

4. **Function References**:
- Ensure that you have referenced the necessary Azure Functions SDK in your project. In a .NET Core or .NET 5/6 project, you should have a reference to the `Microsoft.Azure.Functions.Extensions` package.

5. **Function Configuration**:
- Check your `local.settings.json` or application settings for any configuration issues that might prevent the Azure Functions runtime from initializing correctly.

6. **Function Host Version**:
- Ensure that you have the appropriate version of the Azure Functions host installed. The host version and runtime version should be compatible with your project.

7. **Azure Functions Extension**:
- Make sure you have the Azure Functions extension installed in your development environment. This extension is often required for local debugging and development.

8. **Build and Debug**:
- Rebuild your project and try debugging it locally. Use tools like the Azure Functions extension for Visual Studio Code or Visual Studio to debug and test your functions.

9. **Logs and Errors**:
- Check the Azure Functions runtime logs for any error messages or warnings that might provide clues about why functions are not loading.

10. **Recreate the Function Project**:
- If you suspect that the project might be corrupted or misconfigured, consider creating a new Azure Functions project from scratch and gradually adding your functions to it. This can help identify if the issue is specific to your existing project.

11. **Extensions and Dependencies**:
- Ensure that any extensions or dependencies you're using in your functions are correctly installed and configured. Incorrect or missing dependencies can cause issues.

12. **Azure Functions Tools**:
- Make sure you have the latest version of the Azure Functions tools and Azure Functions Core Tools installed.

13. **Update Azure Functions Runtime**:
- Ensure that you have the latest version of the Azure Functions runtime installed on your Azure hosting environment if you're deploying there.

14. **Azure Function Hosting Plan**:
- Check that your Azure Function App hosting plan is correctly configured and that you are deploying to the correct plan.

By following these steps and carefully checking your project's structure, code, and configuration, you should be able to identify and resolve the `"0 functions loaded"` issue for your .NET Azure Function.

/cc @FinVamp1 @sidkri @paulyuk @vrdmr @mattchenderson @fabiocav

Start by verifying the proposed causes against the project structure, csproj, FunctionName.cs, local.settings.json, runtime logs, and Azure Functions tools mentioned in the issue. Compare current troubleshooting steps for dotnet and dotnet-isolated apps. Done means validated public documentation with separate guidance for both models and corrections to unsupported advice.

Written by the indexing model from the issue text.