No way to add a dll path in linux is explain

### Type of issue

Missing information

### Description

UserDirectories talk about adding your own path but does not provide the way to do it within dotnet nor does it talk about other platforms.

A more standardize way to do it would be appreciated (ex: a standard C# call).

```

UserDirectories | 1024 | Include any path that was explicitly added to the process-wide search path by using the Win32 AddDllDirectory function.
-- | -- | --

```

### Page URL

https://learn.microsoft.com/en-us/dotnet/api/system.runtime.interopservices.dllimportsearchpath?view=net-9.0

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Runtime.InteropServices/DllImportSearchPath.xml

### Document Version Independent Id

51afbafa-f221-460a-b17f-49555bbc3067

### Platform Id

ec2e5ce7-ecaa-3422-83e3-7f8e1ca47e12

### Article author

@dotnet-bot