docs(ridfire)

Added more documentation, also moved all engine code into
gridfire::engine namespace to be more in line with other parts of teh
code base

src/include/gridfire/reaction/weak/weak.h

@@ -569,7 +569,6 @@ namespace gridfire::rates::weak {
                 log_rhoYe
             );
 
-            // TODO: Clean this up. When a bit of code needs this many comments to make it clear it is bad code
             if (!result.has_value()) {
                 bool okayToClamp = true;
                 const auto&[errorType, boundsErrorInfo] = result.error();