Double parameter metadata.
Ported from: https://code.usgs.gov/ghsc/nshmp/nshmp-haz-v2 /-/blob/master/src/main/java/gov/usgs/earthquake/nshmp/www/meta/DoubleParameter.java
Double parameter metadata.
Ported from: https://code.usgs.gov/ghsc/nshmp/nshmp-haz-v2 /-/blob/master/src/main/java/gov/usgs/earthquake/nshmp/www/meta/DoubleParameter.java