is_homepage is False if the homepage contains subpages

[joserebelo]

Our homepage contains multiple subpages:

nav:
  - Home:
    - index.md
    - page2.md
    - page3.md

In the is_homepage property:

mkdocs/mkdocs/structure/pages.py

Lines 134 to 136 in 7186f4c

	def is_homepage(self) -> bool:
	"""Evaluates to `True` for the homepage of the site and `False` for all other pages."""
	return self.is_top_level and self.is_index and self.file.url in ('.', './', 'index.html')

the page.is_top_level property is False for the homepage index page, even though it is indeed the homepage and served at root level.

Using the Material for MkDocs theme, although I don't think it's related.