Add std normal

[ericward-noaa]

• include CDF for normal
• possibly with / without estimated detection threshold
• possibly with / without variance mean linear relationship
• add all to delta models

[ericward-noaa]

TMB has pnorm() with same syntax as R

[seananderson]

What is this referring to exactly? Fitting a Gaussian curve?

[ericward-noaa]

No -- this is the eDNA related cumulative distribution model -- I've got it locally and on a branch (I think) but will wrap this up soon

[ericward-noaa]

Needs: (1) multiple offsets. For example there's 3 included in the model from Ole's paper (see eqn 1.2), (2) resolving log10() vs ln(), (3) log10 copies vs Ct in log10 space is linear -- and fit with hierarchical model random slopes and random intercepts. (4) add ability to take in a new dataframe for fitting the model