Fix noop if flags are empty and use Sprintfs

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

docs.go

@@ -54,8 +54,6 @@ func (a *App) writeDocTemplate(w io.Writer) error {
 	})
 }
 
-const nl = "\n"
-
 func prepareCommands(commands []Command, level int) []string {
 	coms := []string{}
 	for i := range commands {
@@ -73,9 +71,8 @@ func prepareCommands(commands []Command, level int) []string {
 
 		flags := prepareArgsWithValues(command.Flags)
 		if len(flags) > 0 {
-			prepared += nl
+			prepared += fmt.Sprintf("\n%s", strings.Join(flags, "\n"))
 		}
-		prepared += strings.Join(flags, nl)
 
 		coms = append(coms, prepared)
 
@@ -113,21 +110,21 @@ func prepareFlags(
 				modifiedArg += sep
 			}
 			if len(trimmed) > 1 {
-				modifiedArg += "--" + trimmed
+				modifiedArg += fmt.Sprintf("--%s", trimmed)
 			} else {
-				modifiedArg += "-" + trimmed
+				modifiedArg += fmt.Sprintf("-%s", trimmed)
 			}
 		}
 		modifiedArg += closer
 		if flag.TakesValue() {
-			modifiedArg += "=" + value
+			modifiedArg += fmt.Sprintf("=%s", value)
 		}
 
 		if addDetails {
 			modifiedArg += flagDetails(flag)
 		}
 
-		args = append(args, modifiedArg+nl)
+		args = append(args, modifiedArg+"\n")
 
 	}
 	sort.Strings(args)