Show usage (short) help if command line parameter is wrong (#5780)

Show usage (short) help if command line parameter is wrong
Show extended (full) help message with pwsh -h
Split Help message on Usage and Extended

src/Microsoft.PowerShell.ConsoleHost/host/msh/CommandLineParameterParser.cs

@@ -394,6 +394,10 @@ namespace Microsoft.PowerShell
             Dbg.Assert(_helpText != null, "_helpText should not be null");
             _hostUI.WriteLine("");
             _hostUI.Write(_helpText);
+            if (_showExtendedHelp)
+            {
+                _hostUI.Write(ManagedEntranceStrings.ExtendedHelp);
+            }
             _hostUI.WriteLine("");
         }
 
@@ -536,6 +540,7 @@ namespace Microsoft.PowerShell
                 else if (MatchSwitch(switchKey, "help", "h") || MatchSwitch(switchKey, "?", "?"))
                 {
                     _showHelp = true;
+                    _showExtendedHelp = true;
                     _abortStartup = true;
                 }
                 else if (MatchSwitch(switchKey, "noexit", "noe"))
@@ -955,7 +960,7 @@ namespace Microsoft.PowerShell
                     }
                     WriteCommandLineError(
                         string.Format(CultureInfo.CurrentCulture, CommandLineParameterParserStrings.ArgumentFileDoesNotExist, args[i]),
-                        showBanner: false);
+                        showHelp: true);
                     return false;
                 }
 
@@ -1164,6 +1169,7 @@ namespace Microsoft.PowerShell
         private string _configurationName;
         private PSHostUserInterface _hostUI;
         private bool _showHelp;
+        private bool _showExtendedHelp;
         private bool _showBanner = true;
         private bool _noInteractive;
         private string _bannerText;

src/Microsoft.PowerShell.ConsoleHost/host/msh/ManagedEntrance.cs

@@ -74,7 +74,7 @@ namespace Microsoft.PowerShell
                 var formattedBanner = string.Format(CultureInfo.InvariantCulture, banner, PSVersionInfo.GitCommitId);
                 exitCode = Microsoft.PowerShell.ConsoleShell.Start(
                     formattedBanner,
-                    ManagedEntranceStrings.ShellHelp,
+                    ManagedEntranceStrings.UsageHelp,
                     args);
             }
             catch (System.Management.Automation.Host.HostException e)

src/Microsoft.PowerShell.ConsoleHost/resources/ManagedEntranceStrings.resx

@@ -124,7 +124,7 @@ Copyright (c) Microsoft Corporation. All rights reserved.
 https://aka.ms/pscore6-docs
 Type 'help' to get help.</value>
   </data>
-  <data name="ShellHelp" xml:space="preserve">
+  <data name="UsageHelp" xml:space="preserve">
     <value>Usage: pwsh[.exe] [[-File] &lt;filePath&gt; [args]]
                   [-Command { - | &lt;script-block&gt; [-args &lt;arg-array&gt;]
                                 | &lt;string&gt; [&lt;CommandParameters&gt;] } ]
@@ -137,7 +137,10 @@ Type 'help' to get help.</value>
 
 PowerShell Online Help https://aka.ms/pscore6-docs
 
-All parameters are case-insensitive.
+All parameters are case-insensitive.</value>
+  </data>
+  <data name="ExtendedHelp" xml:space="preserve">
+    <value>
 
 -Command | -c
     Executes the specified commands (and any parameters) as though they were typed