Small suggestion: Add /ot to the list of synonyms for /ask and /btw

### Describe the feature or problem you'd like to solve

The first time I wished the feature existed, I tried typing /ot (for off-topic). That was my first instinct, and others might have the same.

### Proposed solution

What the title says: Add /ot to the list of synonyms for /ask and /btw.

Off-topic has a good correlation with what the feature is about. I guess it depends on their mental model. I just think it can be more intuitive for some people to type /ot than /ask or /btw. Unless you are reserving /ot for something else, I think it's an easy win.

### Example prompts or workflows

/ot what is the command to block inbound traffic based on ip address?

### Additional context

_No response_

首先在 CLI 中找到 /ask 和 /btw 的命令定義或同義詞列表。將 /ot 新增為別名，然後驗證如 issue 中範例所示的 /ot prompt 是否遵循與 /ask 和 /btw 相同的工作流程。

由索引模型根據 Issue 內容生成。