update docs for linear/exp functions
update docs for linear/exp functions

mbmcgarry/cyclus,hodger/cyclus,hodger/cyclus,rwcarlsen/cyclus,gidden/cyclus,gidden/cyclus,hodger/cyclus,rwcarlsen/cyclus,hodger/cyclus,rwcarlsen/cyclus,Baaaaam/cyclus,mbmcgarry/cyclus,mbmcgarry/cyclus,gidden/cyclus,Baaaaam/cyclus,rwcarlsen/cyclus,hodger/cyclus,mbmcgarry/cyclus,gidden/cyclus,Baaaaam/cyclus