[User Story] As a developer, I want to be able to make issue references inside project channels

**Given...**
Given I accept the bot to overwrite my messages with issue references (by a command like `c!github iss-ref true`)

**When...**
When I send a message with a issue reference in a project channel.

> We shall fix #69 and merge #70 quickly

**Then...**
Then the bot copy my message, deletes it and resend referencing the issue. (using a hyperlink)

> [{user}]: We shall fix [#69]\(https://github.com/Code2Gether-Discord/{channel}/issue/69) and merge [#70]\(https://github.com/Code2Gether-Discord/{channel}/pull/70)

首先定位 `c!github iss-ref true` 的 bot 命令处理逻辑，以及项目频道的消息处理入口。跟踪消息的接收、删除和重新发送过程，然后分别通过引用 issue 和 pull request 来验证行为。完成的标准是：选择加入的用户所发送的消息会被替换为超链接，而其他消息保持不变。

由索引模型根据 Issue 内容生成。