sidebar now takes glob-patterns as config values

[svennergr]

The sidebar plugin can now take glob-patterns as config values aswell. You still can configure it with a single string with:

export default {
    srcDir: '.',
    include: ['**/*.md'],
    theme: 'docs',
    plugins: ['sidebar', 'prev_next'],
    sidebar: {
        '/deep/': [
            'deep/foo/README.md',
            'deep/bar/README.md'
        ]
    },
};

or with a glob pattern:

export default {
    srcDir: '.',
    include: ['**/*.md'],
    theme: 'docs',
    plugins: ['sidebar', 'prev_next'],
    sidebar: {
        '/deep/': [
            'deep/**/*.md'
        ]
    },
};