Research adding a calendar of meetup events to current homepage

While we wait on #67, let's figure out the work involved here.

I think this was done on the original homepage, so should mostly involve copying and pasting from there. Opening this issue to track what's involved.

比較目前的 homepage 與 issue 中參照的原始 homepage，並檢視 issue #67 以了解背景脈絡。完成的定義是：記錄新增 meetup-event calendar 所需的工作，並將該範圍記錄在此 issue 中。

由索引模型根據 Issue 內容生成。