Make it clear that @id is URIpath with / seperators

[stain]

Added below Core Metadata for Data Entities to clarify #77

Encoding file paths

Note that all @id identifiers must be valid URI references, care must be taken to express any relative paths using / separator, correct casing, and escape special characters like space (%20) and percent (%25), for instance a File Data Entity from the Windows path Results and Diagrams\almost-50%.png becomes "@id": "Results%20and%20Diagrams/almost-50%25.png" in the RO-Crate JSON-LD.

In this document the term URI includes international _IRI_s; the RO-Crate Metadata File is always UTF-8 and international characters in identifiers SHOULD be written using native UTF-8 characters (_IRI_s), however traditional URL encoding of Unicode characters with % MAY appear in @id strings. Example: "@id": "面试.mp4" is preferred over the equivalent "@id": "%E9%9D%A2%E8%AF%95.mp4"

[stain]

Would @marcolarosa or @ptsefton be able to review?

[marcolarosa]

@stain Yep - that makes sense and it looks like that commit is putting that text into Core Metadata for Entities section which I think is also a good place for it.