Add Troubleshooting section to Discord docs (#7700)

* Add Troubleshooting section

* Apply suggestions from code review

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Co-authored-by: vivianyentran <20403606+vivianyentran@users.noreply.github.com>

src/docs/product/accounts/early-adopter-features/discord/index.mdx

@@ -82,3 +82,13 @@ All users in any Discord server with the Sentry bot can use the `/link` command
 ![Discord identity linking page](discord-identity-link-page.png)
 
 To unlink your accounts, use the `/unlink` command. Follow the link and click "Unlink from Discord"
+
+### Troubleshooting
+
+#### Your channel ID isn't working in the alert creation wizard
+
+If you're trying to create an alert with a Discord action and Sentry can't access the channel you've provided, please double-check the following:
+
+- You are giving us a channel ID and not a channel name or something else. See [Configure](#configure) for more details.
+- The channel you're trying to add is in the same server that is selected in the alert action.
+- The bot has access to the channel you're trying to use. A quick way to verify this is to check whether you can find the bot in the desired channel's member list. If you do not see the bot in the list of users, you may need to update your Discord role and/or channel permissions to allow the bot access. See [Install](#install) for more details.