getMemberCommunities = async (req, res) => {
  try {
    const communities = await Community.find({
      members: {
        $in: [req.userId],
      },
    })
      .select("_id name banner members description")
      .lean();

    res.status(200).json(communities);
  } catch (error) {
    res.status(500).json({
      message: "Error getting communities",
    });
  }
}
Retrieves all communities that a user is a member of, including the community's ID,
name, banner image, member count, and description.

@route GET /communities/member