Add distribution digest

[andrea-perego]

Relevant issue: #1287

Summary of changes:

• Add property spdx:checksum to dcat:Distribution
• Add class spdx:Checksum (range of property spdx:checksum) and related properties spdx:algorithm and spdx:checksumValue
• Add SPDX to the namespace table
• Update changelog accordingly

Preview of the newly added sections:

• https://raw.githack.com/w3c/dxwg/dcat-distribution-digest/dcat/index.html#Property:distribution_checksum
• https://raw.githack.com/w3c/dxwg/dcat-distribution-digest/dcat/index.html#Class:Checksum

Diff: https://services.w3.org/htmldiff?doc1=https%3A%2F%2Fw3c.github.io%2Fdxwg%2Fdcat%2F&doc2=https%3A%2F%2Fraw.githack.com%2Fw3c%2Fdxwg%2Fdcat-distribution-digest%2Fdcat%2Findex.html

[agbeltran]

thanks for addressing my previous comments @andrea-perego - I suggest we add a reference to https://spdx.dev in addition to the vocabulary (as it provides a lot more information about the vocabulary and its governance)

[riannella]

@agbeltran I agree that the definition provided by SPDX is not clear (authenticity V integrity) - but since we are reusing their property then we have to use the same definition. Perhaps we should make this feedback available to the SPDX team?

[agbeltran]

@riannella I agree we should feed this back to the SPDX community, but the changes we are making in the definition are more clarifications than changing the essense of the property, so I don't think we need to copy the definition verbatim (and we should say that the definition is based on SPDX) - what do others think?

[riannella]

@riannella I agree we should feed this back to the SPDX community, but the changes we are making in the definition are more clarifications than changing the essense of the property, so I don't think we need to copy the definition verbatim (and we should say that the definition is based on SPDX) - what do others think?

Done: spdx/spdx-spec#500

I am happy for us to adopt this update now.

[agbeltran]

@riannella I agree we should feed this back to the SPDX community, but the changes we are making in the definition are more clarifications than changing the essense of the property, so I don't think we need to copy the definition verbatim (and we should say that the definition is based on SPDX) - what do others think?

Done: spdx/spdx-spec#500

I am happy for us to adopt this update now.

that's brilliant - thanks @riannella

[andrea-perego]

thanks for addressing my previous comments @andrea-perego - I suggest we add a reference to https://spdx.dev in addition to the vocabulary (as it provides a lot more information about the vocabulary and its governance)

Thanks, @agbeltran . Could you please suggest the actual revision to be made?

BTW, I just saw that now https://spdx.org/ (pointing to the old Web site) redirects to https://spdx.dev/ (the new one), so probably this revision is no longer needed.

[andrea-perego]

@riannella I agree we should feed this back to the SPDX community, but the changes we are making in the definition are more clarifications than changing the essense of the property, so I don't think we need to copy the definition verbatim (and we should say that the definition is based on SPDX) - what do others think?

Done: spdx/spdx-spec#500
I am happy for us to adopt this update now.

that's brilliant - thanks @riannella

Thanks, @agbeltran & @riannella .

Revision implemented via commit 8c64f98

[andrea-perego]

thanks for addressing my previous comments @andrea-perego - I suggest we add a reference to https://spdx.dev in addition to the vocabulary (as it provides a lot more information about the vocabulary and its governance)

Thanks, @agbeltran . Could you please suggest the actual revision to be made?

BTW, I just saw that now https://spdx.org/ (pointing to the old Web site) redirects to https://spdx.dev/ (the new one), so probably this revision is no longer needed.

@agbeltran , I'm now going to merge this PR, as this is just an editorial revision that can be implemented in a new PR.