Cleanup work of jlreq repository after jlreq-d was created

[kidayasuo]

Cleanup of or moving jlreq-d related issues. Moving files from /docs. etc.

[himorin]

relevant directory in /docs/ seems to be as followings?:

• JDLReq_overview : copied into jlreq-d repository as README+
• spacing_property : this is a basis of jlreq-d character class, should be moved into jlreq-d/docs (or somewhere)

wondering for followings, which could be used as a draft text for a part of jlreq-d:

• layout_of_punctuations
• line-composition