[Suggestion] Add a troubleshooting about sending images of feishu channel

[Bennett-Yang]

I cannot send image through feishu channel for a long time. I thought feishu does not support sending images. It turns out "im:resource" permission need to be enabled for feishu robot. Maybe a troubleshooting about failing to send images through feishu channel should be added on the page https://nanobot.wiki/docs/0.4.0/guides/feishu-ai-agent#troubleshooting

[chengyongru]

this is reasonable