Minor bugfix for enum parsing

Author: Turnerj

Source/Common/Constants.cs

@@ -6,12 +6,12 @@ namespace Schema.NET
     public static class Constants
     {
         /// <summary>
-        /// The HTTPS URL for Schema.org
+        /// The HTTPS URL for Schema.org, excluding trailing slash.
         /// </summary>
         public const string HttpsSchemaOrgUrl = "https://schema.org";
 
         /// <summary>
-        /// The HTTPS URL for Schema.org
+        /// The HTTP URL for Schema.org, excluding trailing slash.
         /// </summary>
         public const string HttpSchemaOrgUrl = "http://schema.org";
     }

Source/Common/EnumHelper.cs

@@ -64,13 +64,13 @@ public static bool TryParseEnumFromSchemaUri(
             if (value is not null && value.StartsWith(Constants.HttpSchemaOrgUrl, StringComparison.OrdinalIgnoreCase))
             {
 #pragma warning disable IDE0057 // Use range operator. Need to multi-target.
-                enumString = value.Substring(Constants.HttpSchemaOrgUrl.Length);
+                enumString = value.Substring(Constants.HttpSchemaOrgUrl.Length + 1);
 #pragma warning restore IDE0057 // Use range operator. Need to multi-target.
             }
             else if (value is not null && value.StartsWith(Constants.HttpsSchemaOrgUrl, StringComparison.OrdinalIgnoreCase))
             {
 #pragma warning disable IDE0057 // Use range operator. Need to multi-target.
-                enumString = value.Substring(Constants.HttpsSchemaOrgUrl.Length);
+                enumString = value.Substring(Constants.HttpsSchemaOrgUrl.Length + 1);
 #pragma warning restore IDE0057 // Use range operator. Need to multi-target.
             }
             else