Documentation inconsistency in the energy derivation in the shallow water model

Hi, I would like to discuss the derivation of the energy calculation of the shallow water model in the Analysis section: [Link to section](https://speedyweather.github.io/SpeedyWeatherDocumentation/dev/analysis#Energy) I think there are some issues/mixups: First, as stated before equations (1) and (2), the potential energy density is $gz$ (ignoring density here). To obtain the potential energy, one must integrate over the volume, i.e. over $z$ from the bottom $H_B$ to the fluid height $H_b + h = H + \eta$. Therefore, equation (1) should read instead: $$E = \iint \left[ \int_{H_b}^{H_b + h} \frac{1}{2} (u^2 + v^2 + 2gz) \ dz \right] dA$$ This then leads to $$E = \iint \frac{1}{2} (u^2 + v^2 + gh + 2H) h \ dA$$ opposed to equation (2). However, since we are only interested in changes of total energy over time (in this section), the constant term $Hh$, which is proportional to the total mass (shown constant in the previous section), can be canceled. This finally (after a few intermediate steps) becomes equivalent to equation (2) in the documentation. Also, in the code snippet following the derivation: `E = @. h/2*(u^2 + v^2) + g*h^2 # vertically-integrated mechanical energy` a factor of `1/2` seems to be missing in front of `g*h^2`. But this somehow almost doesn't matter, although `1/2` leads to slightly better energy conservation over time (in my own testing).