Improve readability of annotation syntaxes

還沒有人認領這個 Issue。

The [method currently used](http://localhost:3000/wiki/annotations/#understanding-this-page) for describing how to use annotations can be easy to understand at times:
`---@type `

And also impossible for mere mortals to understand:
`---@cast [+|-][, [+|-]...]`
`---@overload fun([param: type[, param: type...]]): [return_value[,return_value]]`

There must be a better way to represent these more complex syntaxes while also not using symbols regularly in use (`<`, `>`, `(`, `)`, `[`, `]`, `{`, `}`, `@`, `#`, `-`, `+`, `=`, `:`, `"`, `,`, `.`, `?`). Although now that I have listed some in-use symbols, I realize we really are quite limited. It is hard to explain a syntax that uses many symbols… using symbols.

I'm open to any suggestions on how this can be improved 🙂

從連結的 annotations/#understanding-this-page 頁面開始，並檢視 issue 中顯示的複雜語法範例。該 issue 沒有定義偏好的替代方案或明確的完成測試；要視為完成，必須就更易讀的表示法達成共識，並更新文件範例。

由索引模型根據 Issue 內容生成。