Add link support for supported terminals

Also refactors the code quite a bit, to make it a bit more
easier to add features like this in the future.

Closes #75

src/Spectre.Console/Capabilities.cs

@@ -11,6 +11,17 @@ namespace Spectre.Console
         /// </summary>
         public bool SupportsAnsi { get; }
 
+        /// <summary>
+        /// Gets a value indicating whether or not
+        /// the console support links.
+        /// </summary>
+        /// <remarks>
+        /// There is probably a lot of room for improvement here
+        /// once we have more information about the terminal
+        /// we're running inside.
+        /// </remarks>
+        public bool SupportLinks => SupportsAnsi && !LegacyConsole;
+
         /// <summary>
         /// Gets the color system.
         /// </summary>