Add GitHub issue templates

There are some error types that we might except to happen, and we should have forums that request log information for those specific errors.

For example, an uncaught JsonSyntaxException implies that the OpenAI api changed, and now the data classes are out of date. We should have an error specifically for that case.

Possible issue types:
* JsonSyntaxException
* Bug Report
* Feature Request

未指定任何檔案、測試或進入點。首先釐清目標是 GitHub issue 表單／範本、特定錯誤表單，還是兩者皆是；然後檢查儲存庫現有的 GitHub 設定，並為每個範本定義必要欄位和完成條件。

由索引模型根據 Issue 內容生成。