chore(docs): Markdown housekeeping

[bartelink]

related: #1966

• Remove year (2020) from copyright message on readme (note this propagates to nuget)
• Remove mention of gitter (it's not well-monitored, so better to have people use GitHub issues and/or PRs to to/fro ideas)
• Added NuGet package copyright (see far bottom right of https://www.nuget.org/packages/equinox)

Open issues:

• Some files are missing copyright headers. Many have incomplete years.

  I feel the best answer is to remove them in favor of having one copyright year range in the NOTICE. This seems to be valid based on https://www.apache.org/legal/apply-license.html#copy-per-file and general SO searching. If this is not agreed, perhaps I could remove them from the test files only?

  Failing that, I can add the header to all source files.

[bartelink]

This flows up to the nuget landing page/ package metadata (and I think the FILEVERSIONINFO on the DLL)

[bartelink]

Hm the Authors in the package (i.e., <Authors>Serilog Contributors</Authors>) might get appended in some renderings?

[bartelink]

Seems they are complementary per https://learn.microsoft.com/en-us/nuget/create-packages/package-authoring-best-practices#copyright, so leaving it that way

[bartelink]

Thoughts on the open issue (in the overview) ? (i.e. add missing copyright headers in impl/test files and/or a copyright to the LICENSE and/or adjust the years per file) ?

[nblumhardt]

RE the copyright headers, I think sorting out the year range (© in the source files where they appear, and full range in the LICENSE file) would be my preference; no super strong feelings there though.

[bartelink]

Not sure what sorting out the year range would mean; make them consistent and then update them every year?
Ensure they reflect the time of last edit per file?
Or strip off the date in the headers?

Happy to do anything of the following that you want
0. just leave it

1. add copyright and year range in LICENSE
2. remove years in file headers, leaving it as Copyright © Serilog Contributors or maybe Copyright 2013- ...
3. add headers to all source files missing them
4. add headers to all test files missing them
5. remove all headers from source files

[bartelink]

aside/unrelated: @nblumhardt can you have a peep at File sink PR 258 please?
Happy to continue reviewing until xmldoc aligns with impl, but perhaps it should just be called off as the motivation/need seems dubious at this point

[nblumhardt]

Thanks for the follow-up. I think even just (2) - using Copyright © Serilog Contributors, and (3) add them consistently to all source files would do the trick, if that sounds good to you?

[bartelink]

@nblumhardt thanks for the response - will merge this and do it as a fresh PR another time

One final question: do I remove headers from test files (a number 6 option I didnt propose!), or apply them consistently same as for source files (i.e. 4) ?

[nblumhardt]

I'm fine either way on the test files - they don't tend to "travel" like the source files do (e.g. Azure/serilog-sinks-azuredataexplorer#16).

[bartelink]

Hm, having seen that I'll apply them to the test files too, unless that becomes a truly huge change..