changes to address latency use case, event speed thresholds, and more

[BenGardiner]

Some larger changes are collected here. The following issues are addressed in this changeset:

• Performance Thresholds object does not need to be retrievable via id in progress -- #133
• Spurious 'Get' on action names in progress -- #131
• error status return codes should all have descriptive bodies in progress -- #130
• Log Events and unit conversion Notes attention wanted in progress -- #127
• Include speed change event recording attention wanted in progress -- #114
• TSP latency reporting attention wanted in progress -- #110
• add section anchors and then also xref sections in progress -- #50

I've updated the preview site: https://app.apiary.io/previewotapi/editor ; see the 'files changed' tab for details.

These changes are not intended to be made for the may prototype; the version of this API for the prototype was frozen at tag https://github.com/nmfta-repo/nmfta-opentelematics-api/releases/tag/protoype-0.1rc.3

[BenGardiner]

@jmpopper , @krishnaswin : please let me know if there are any changes here that you would rather include in the prototype. We can cherry-pick them and spin another tagged release for anything that you think would make the prototyping easier / better for you.

[BenGardiner]

I executed the rest of the changes;

• Get Vehicle Flagged Events should return a collection in progress -- #141
• missing 404s on get-by-id in progress -- #140
• duplicate .../stops/{id} in progress -- #139
• Add State of Health to the get-by-id group in progress -- #138
• note the Log Events exception to SI in progress -- #137
• make it clear that Log Events are in Miles or KMs but not required to be both in progress -- #136
• make it clear that ECU speed is the threshold speed in progress -- #135
• improve action grouping based on generated SDK in progress -- #132

I've updated the apiary site https://previewotapi.docs.apiary.io

and the apimatic site https://www.apimatic.io/apidocs/nmfta-opentelematics-api/v/0_1-rc_5#