[Feature] Update library documentation (#580)

* Minor IHardware doc fixes

* Add XML with documentation to NuGet and output

* Update Software namespace docs

* Update some internal classes

* Update main Computer class docs

* Update interfaces docs

* Update Computer class documentation

* Update motherboard docs

* Update hardware docs

* Fix code formatting

* Update SensorVisitor handler doc

LibreHardwareMonitorLib/Interop/Ring0.cs

@@ -8,6 +8,9 @@
 
 namespace LibreHardwareMonitor.Interop
 {
+    /// <summary>
+    /// Driver with access at kernel level.
+    /// </summary>
     internal static class Ring0
     {
         public const uint INVALID_PCI_ADDRESS = 0xFFFFFFFF;

LibreHardwareMonitorLib/Interop/WinNt.cs

@@ -10,10 +10,16 @@ using System.Runtime.InteropServices;
 
 namespace LibreHardwareMonitor.Interop
 {
+    /// <summary>
+    /// Contains Win32 definitions for Windows NT.
+    /// </summary>
     internal static class WinNt
     {
         internal const int STATUS_SUCCESS = 0;
 
+        /// <summary>
+        /// Describes a local identifier for an adapter.
+        /// </summary>
         [StructLayout(LayoutKind.Sequential)]
         internal struct LUID
         {
@@ -21,6 +27,9 @@ namespace LibreHardwareMonitor.Interop
             public readonly int HighPart;
         }
 
+        /// <summary>
+        /// Represents a 64-bit signed integer value.
+        /// </summary>
         [StructLayout(LayoutKind.Explicit, Size = 8)]
         internal struct LARGE_INTEGER
         {