Proposed change of hgv_time_restrictions field to Time Domain from GDF 5.1

[roman-ianivskyy]

… and shorter format of Time Domain from GDF 5.1

• Update tests
• Update docs

[roman-ianivskyy]

Hello, @nvkelso, could you please check this proposed change to time format for HGV restrictions? I assume it was not yet included in Tilezen datasources. Or if it was already released - what is the process for such breaking changes?

[nvkelso]

Please address the nits in the documentation and then I'll approve.

Tilezen uses documents our implementation of SemVer in

• https://github.com/tilezen/vector-datasource/blob/master/docs/SEMANTIC-VERSIONING.md#patch-version-increments

Since this is an optional roads layer property, it isn't explicitly covered in the contract (which is mostly focused on layers, kinds, and min_zoom changes. Adding optional properties is in minor version. Modifying the value definitions (since this is really a large reclassification) would fall into MINOR or PATCH territory. But we'll tag it in the upcoming v1.9 release and can merge this PR when you're ready with the changes.

We've never added support for it in the mainline vector-datasource repo here, which also gives some more flexibility.

[nvkelso]

Left one nit about number of weeks in a year.