Mark crawler-created(-only) properties in the ontology

[hoijui]

Also mark properties that change their values when crawling,
like file-paths or URLs to source files, which might change from a repo-relative path
to a URL with a fixed commit hash in it.

This might be interesting for at least a GUI editor in the future,
to know which properties definitely do not have to or should not be supplied,
but also for humans inspecting the ontology.

[moedn]

jepp, that sounds good 👌

so practically we have:

1. properties created by the crawler
2. properties created by developers using manifest files
3. properties pulled from external sources (using the crawler) that do not have any equivalent in OKH-LOSH

The ontology includes all 3 while we need dedicated specifications for 2 & 3.

Clarification for 3: OKH-LOSH doesn't aim to be the one-size-fits-all specification (as OKHv1 intends to); its goal is to bridge the necessary gaps between the data formats of different data sources to be eventually able to handle messy data. Some data will only be available from some specific sources, but useful for users nonetheless – e.g. certification date for projects extracted from OSHWA