Modernize GetLogicalDrives docs (#10376)

Author: MSDN-WhiteKnight

xml/System.IO/Directory.xml

@@ -4055,13 +4055,13 @@ The returned collection is not cached. Each call to the <xref:System.Collections
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Retrieves the names of the logical drives on this computer in the form "&lt;drive letter&gt;:\\".</summary>
-        <returns>The logical drives on this computer.</returns>
+        <summary>Retrieves the names of the logical drives on this computer.</summary>
+        <returns>An array of strings representing the logical drive names.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- GetLogicalDrives returns all of the accessible drives on a particular machine, including the floppy drive and any optical drives.
+ On Windows, `GetLogicalDrives` returns the names of all accessible drives on a particular machine, including any optical drives or removable media devices, in the form "\<drive letter\>:\\" (for example, "C:\\"). On Unix, it returns the paths of all filesystem mount points mounted on a particular machine (for example, "/home/user", "/media/usb").
 
  For a list of common I/O tasks, see [Common I/O Tasks](/dotnet/standard/io/common-i-o-tasks).
 

xml/System/Environment.xml

@@ -1421,11 +1421,14 @@ The following example creates environment variables for the <xref:System.Environ
       </ReturnValue>
       <Parameters />
       <Docs>
-        <summary>Returns an array of string containing the names of the logical drives on the current computer.</summary>
-        <returns>An array of strings where each element contains the name of a logical drive. For example, if the computer's hard drive is the first logical drive, the first element returned is "C:\\".</returns>
+        <summary>Retrieves the names of the logical drives on this computer.</summary>
+        <returns>An array of strings representing the logical drive names.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[
 
+## Remarks
+ On Windows, `GetLogicalDrives` returns the names of all accessible drives on a particular machine, including any optical drives or removable media devices, in the form "\<drive letter\>:\\" (for example, "C:\\"). On Unix, it returns the paths of all filesystem mount points mounted on a particular machine (for example, "/home/user", "/media/usb").
+
 ## Examples
  The following example shows how to display the logical drives of the current computer using the <xref:System.Environment.GetLogicalDrives%2A> method.