feat: Generate admin command documentation

The first part of getting admin command docs on the website.

There's also the beginnings of manpage generation here, although it's
kinda sus and I'm not sure how it's supposed to work. I'll leave that to
anyone who wants to package it.

We introduce the beginings of the xtask pattern here - we do a lot of
file generation, I thought it would be best to avoid doing that on every
compilation. It also helps avoid lots of runtime deps.

We'll need to document generating this stuff & probably add pre-commit
hooks for it, though.

src/admin/room/alias.rs

@@ -8,7 +8,7 @@ use ruma::{OwnedRoomAliasId, OwnedRoomId};
 use crate::Context;
 
 #[derive(Debug, Subcommand)]
-pub(crate) enum RoomAliasCommand {
+pub enum RoomAliasCommand {
 	/// - Make an alias point to a room.
 	Set {
 		#[arg(short, long)]

src/admin/room/directory.rs

@@ -6,7 +6,7 @@ use ruma::OwnedRoomId;
 use crate::{Context, PAGE_SIZE, get_room_info};
 
 #[derive(Debug, Subcommand)]
-pub(crate) enum RoomDirectoryCommand {
+pub enum RoomDirectoryCommand {
 	/// - Publish a room to the room directory
 	Publish {
 		/// The room id of the room to publish

src/admin/room/info.rs

@@ -7,7 +7,7 @@ use crate::{admin_command, admin_command_dispatch};
 
 #[admin_command_dispatch]
 #[derive(Debug, Subcommand)]
-pub(crate) enum RoomInfoCommand {
+pub enum RoomInfoCommand {
 	/// - List joined members in a room
 	ListJoinedMembers {
 		room_id: OwnedRoomId,

src/admin/room/mod.rs

@@ -16,7 +16,7 @@ use crate::admin_command_dispatch;
 
 #[admin_command_dispatch]
 #[derive(Debug, Subcommand)]
-pub(super) enum RoomCommand {
+pub enum RoomCommand {
 	/// - List all rooms the server knows about
 	#[clap(alias = "list")]
 	ListRooms {

src/admin/room/moderation.rs

@@ -12,7 +12,7 @@ use crate::{admin_command, admin_command_dispatch, get_room_info};
 
 #[admin_command_dispatch]
 #[derive(Debug, Subcommand)]
-pub(crate) enum RoomModerationCommand {
+pub enum RoomModerationCommand {
 	/// - Bans a room from local users joining and evicts all our local users
 	///   (including server
 	/// admins)