[BUG] Markdown inside a layout

[polyedre]

Describe the bug

When printing a Markdown object inside a Layout, the rendering only prints the title.

To Reproduce

from rich.markdown import Markdown
from rich.layout import Layout
from rich import print

MARKDOWN = """
description

# Title
"""

layout = Layout(Markdown(MARKDOWN))
print(layout)

Output:

Platform

Tested on Linux with xterm and alacritty.

Diagnose

flowery ❯ python -m rich.diagnose
╭───────────────────────── <class 'rich.console.Console'> ─────────────────────────╮
│ A high level console interface.                                                  │
│                                                                                  │
│ ╭──────────────────────────────────────────────────────────────────────────────╮ │
│ │ <console width=114 ColorSystem.TRUECOLOR>                                    │ │
│ ╰──────────────────────────────────────────────────────────────────────────────╯ │
│                                                                                  │
│     color_system = 'truecolor'                                                   │
│         encoding = 'utf-8'                                                       │
│             file = <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'> │
│           height = 64                                                            │
│    is_alt_screen = False                                                         │
│ is_dumb_terminal = False                                                         │
│   is_interactive = True                                                          │
│       is_jupyter = False                                                         │
│      is_terminal = True                                                          │
│   legacy_windows = False                                                         │
│         no_color = False                                                         │
│          options = ConsoleOptions(                                               │
│                        size=ConsoleDimensions(width=114, height=64),             │
│                        legacy_windows=False,                                     │
│                        min_width=1,                                              │
│                        max_width=114,                                            │
│                        is_terminal=True,                                         │
│                        encoding='utf-8',                                         │
│                        justify=None,                                             │
│                        overflow=None,                                            │
│                        no_wrap=False,                                            │
│                        highlight=None,                                           │
│                        markup=None,                                              │
│                        height=None                                               │
│                    )                                                             │
│            quiet = False                                                         │
│           record = False                                                         │
│         safe_box = True                                                          │
│             size = ConsoleDimensions(width=114, height=64)                       │
│        soft_wrap = False                                                         │
│           stderr = False                                                         │
│            style = None                                                          │
│         tab_size = 8                                                             │
│            width = 114                                                           │
╰──────────────────────────────────────────────────────────────────────────────────╯
flowery ❯ python -m rich._windows
platform="Linux"
WindowsConsoleFeatures(vt=False, truecolor=False)
flowery ❯ pip freeze | grep rich
rich==10.1.0

[willmcgugan]

Please try v10.2.1

[polyedre]

I confirm that your PR fixed this 🙂 This was such a chirurgical PR! Thanks