It is good practice to wrap all dynamic content in `{% raw %}..{% endraw %}`
Liquid tags so that no syntax within can mistakenly get interpreted as
Liquid tags. Fixes rendering of `gh auth login` help page.
- "Examples" section now renders with syntax highlighting and doesn't
interpret curly braces as Liquid tags anymore
- Flags are now listed with nicer formatting than just being rendered to
a plain text block
- Flags are now listed above the "Examples" section
- The `--help` flag is no longer explicitly and repetitively being
listed as an inherited flag under every command
- Usage synopsis line is now rendered early in the documentation for a
command
- Every command that has subcommands now explicitly lists those
subcommands in its documentation
