docs(release): revise prt/gwe in mf6io and supp tech info (#2104)

Rewrite some of the PRT and GWE supplemental technical info chapters. Also some fixes in PRT section of mf6io. These edits are courtesy of @aprovost-usgs.

Author: wpbonelli

doc/SuppTechInfo/groundwater-energy-model.tex

@@ -114,7 +114,7 @@ \subsubsection{Advanced Stress Packages}
 
 The version of the GWE Model described here offers four advanced stress packages, each of which is analogous and functions similarly to an advanced package in the GWT Model: Lake Energy Transport (LKE), Multi-Aquifer Well Energy Transport (MWE), Streamflow Energy Transport (SFE), and Unsaturated Zone Energy Transport (UZE). The GWE advanced stress packages will not be described in detail here except to note differences from the corresponding GWT packages. The primary difference, of course, is that GWE advanced stress packages explicitly simulate thermal energy transport within their respective features, not solute mass. Optionally, the SSM package may be used to represent the effects of thermal energy exchange between an advanced transport package and the subsurface for cases where the temperature of the feature is known.
 
-The LKE, SFE, and MWE Packages offer a mechanism for energy to conduct between the lake or stream reach and the aquifer through a thermally conductive layer that can represent, for example,  a lake or stream bed or a well casing. The LKT, SFT, and MWT packages do not offer analogous diffusion of solute through the a conductive layer. The LKE and SFE packages also account for removal of thermal energy from surface water by evaporation.
+The LKE, SFE, and MWE Packages offer a mechanism for energy to conduct between the lake or stream reach and the aquifer through a thermally conductive layer that can represent, for example,  a lake or stream bed or a well casing. The LKT, SFT, and MWT packages do not offer analogous diffusion of solute through a conductive layer. The LKE and SFE packages also account for removal of thermal energy from surface water by evaporation.
 
 The UZE Package simulates thermal energy transport through the unsaturated zone. It calculates cell temperatures based on cell-cell flows generated by the Unsaturated Zone Flow (UZF) Package in the GWF Model and the assumption of thermal equilibrium between the water and the solid matrix material. Equilibrium sorption, which can be considered a solute-transport analog of thermal equilibrium, is not currently simulated by the corresponding Unsaturated Zone Transport (UZT) Package in the GWT Model.