Missing phase-rate unit

[speleos]

DAS-metadata/schema/DAS-Metadata.v2.0.schema.json

Line 325 in 1da41a1

"enum": [

Depending on interrogator, raw data might be stored as phase rate instead of counts or strainrate

[javiquinte]

Following the previous issue, the SI units are expected to be declared in that case. For instance, for Optodas (dphi case) use rad/s or rad/m/s.