find: Fix the `find` command, add more options. The `--endpoint` option doesn't make any sense anymore since page sources could have non-file-system endpoints. This was replaced with `--name` to match source names instead. Also added `--include-theme`, with filtering out theme pages by default, and `--exact` to explicitely match the given pattern, with matching anything that contains the pattern by default.

from textile import textile
from piecrust.formatting.base import Formatter


class TextileFormatter(Formatter):
    FORMAT_NAMES = ['textile', 'text']
    OUTPUT_FORMAT = 'html'

    def render(self, format_name, text):
        assert format_name in self.FORMAT_NAMES
        return textile(text)