mdlink: Add option to send mobile-friendly link (#33)

When copying a message on mobile, you have to copy the entire message
anyways, and then you have to remove the backticks. This option allows
the link to be sent escaped instead of in backticks, i.e.,

        \[foo](http:\/\/bar.com)

instead of

        `[foo](http://bar.com)`

Author: L3viathan

mdlink/mdlink.py

@@ -1,4 +1,7 @@
+import typing as t
+
 from discord.ext import commands
+from discord.utils import escape_markdown
 
 from bot import ModmailBot
 from core import checks
@@ -14,10 +17,19 @@ def __init__(self, bot: ModmailBot):
     @commands.command()
     @checks.has_permissions(PermissionLevel.MODERATOR)
     @checks.thread_only()
-    async def mdlink(self, ctx: commands.Context, *, text: str = "ModMail") -> None:
+    async def mdlink(
+        self,
+        ctx: commands.Context,
+        plain: t.Optional[t.Literal["plain", "p", "mobile", "m"]] = None,
+        *,
+        text: str = "ModMail",
+    ) -> None:
         """Return a link to the modmail thread in markdown syntax."""
         link = await self.bot.api.get_log_link(ctx.channel.id)
-        await ctx.send(f"`[{text}]({link})`")
+        if plain:
+            await ctx.send(escape_markdown(f"[{text}]({link})", as_needed=True, ignore_links=False))
+        else:
+            await ctx.send(f"`[{text}]({link})`")
 
 
 async def setup(bot: ModmailBot) -> None: