fill in help topic

pkg/cmd/root/help_topic.go

@@ -9,7 +9,20 @@ var HelpTopics = map[string]map[string]string{
 	"mintty": {
 		"short": "Information about using gh with MinTTY",
 		"long": heredoc.Doc(`
-			TODO
+			MinTTY is the terminal emulator that comes by default with Git
+			for Windows.  It has known issues with gh's ability to prompt a
+			user for input.
+
+			There are a few workarounds to make gh work with MinTTY:
+
+			- Reinstall Git for Windows. 
+			  Be sure to check the box "Enable experimental support for pseudo consoles".
+
+			- Use a different terminal emulator with Git for Windows like Windows Terminal or cmd.exe.
+			  Try running "C:\Program Files\Git\bin\bash.exe" in one of those other terminal emulators.
+
+			- Prefix invocations of gh with winpty, eg: "winpty gh auth login".
+			  NOTE: this can lead to some UI bugs.
 		`),
 	},
 	"environment": {

pkg/cmd/root/root.go

@@ -103,6 +103,7 @@ func NewCmdRoot(f *cmdutil.Factory, version, buildDate string) *cobra.Command {
 	// Help topics
 	cmd.AddCommand(NewHelpTopic("environment"))
 	cmd.AddCommand(NewHelpTopic("formatting"))
+	cmd.AddCommand(NewHelpTopic("mintty"))
 	referenceCmd := NewHelpTopic("reference")
 	referenceCmd.SetHelpFunc(referenceHelpFn(f.IOStreams))
 	cmd.AddCommand(referenceCmd)