Make sure 'rich.markup' is imported when rendering help text

rich.markup is used to escape strings when rendering help texts.

This fixes a regression introduced by fastapi#1128

Author: g-arjones

typer/core.py

@@ -372,6 +372,7 @@ def get_help_record(self, ctx: click.Context) -> Optional[Tuple[str, str]]:
             extra_str = f"[{extra_str}]"
             if rich is not None:
                 # This is needed for when we want to export to HTML
+                import rich.markup
                 extra_str = rich.markup.escape(extra_str).strip()
 
             help = f"{help}  {extra_str}" if help else f"{extra_str}"
@@ -583,6 +584,7 @@ def _write_opts(opts: Sequence[str]) -> str:
             extra_str = f"[{extra_str}]"
             if rich is not None:
                 # This is needed for when we want to export to HTML
+                import rich.markup
                 extra_str = rich.markup.escape(extra_str).strip()
 
             help = f"{help}  {extra_str}" if help else f"{extra_str}"