重新整理标音的脉络

[xfq]

https://w3c.github.io/clreq/#interlinear_annotations

根据会议上的讨论，我们需要重新整理一下这一节的脉络。

[xfq]

Related issue: #355 and #349

[ryukeikun]

Just some references mentioned during the monthly meeting:

The term "Ruby" was referred as small size of type (5.25 pt), and as early as 1900s, The American Presbyterian Mission Press (美华书馆) in Shanghai named its Chinese type in such a size as "珍字", and this name had being used until at least 1980s.

书馆制成七种不同大小的宋体铅字（即1～7号字：一号“显”字，二号“明”字，三号“中”字，四号“行”字，五号“解”字，六号“注”字，七号“珍”字） (《中国印刷通史》)

《凸版排版工艺》，上海出版印刷公司职工大学，1982年4月