Avoid use of at-doc macro inside structs (#642)

In Julia v1.13, using at-doc inside struct to attach the docstring to an inner
constructor causes an extra hidden field to be added to the struct itself, due
to macro expansion rules.  Doesn't look like this is going to be changed
upstream, so we have to work around it: luckily the fix is backward compatible,
we only lose the convenience of having the docstring right above the constructor
definition.

Author: giordano

src/Microphysics/bulk_microphysics.jl

@@ -41,39 +41,39 @@ AtmosphereModels.negative_moisture_correction(bμp::BulkMicrophysics) = bμp.neg
 
 Base.summary(::BulkMicrophysics) = "BulkMicrophysics"
 
-struct NonEquilibriumCloudFormation{L, I}
-    liquid :: L
-    ice :: I
+"""
+    NonEquilibriumCloudFormation(liquid, ice=nothing)
 
-    @doc"""
-        NonEquilibriumCloudFormation(liquid, ice=nothing)
+A cloud formation scheme where cloud liquid and ice are prognostic variables
+that evolve via condensation/evaporation and deposition/sublimation tendencies,
+rather than being diagnosed instantaneously via saturation adjustment.
 
-    A cloud formation scheme where cloud liquid and ice are prognostic variables
-    that evolve via condensation/evaporation and deposition/sublimation tendencies,
-    rather than being diagnosed instantaneously via saturation adjustment.
+The condensation/evaporation and deposition/sublimation tendencies are commonly modeled as **relaxation toward
+saturation** with timescale `τ_relax`, including a latent-heat (psychrometric/thermal) correction factor; see
+[Morrison and Grabowski (2008)](@cite Morrison2008novel), Appendix Eq. (A3), and standard cloud microphysics
+texts such as [Pruppacher and Klett (2010)](@cite pruppacher2010microphysics) or
+[Rogers and Yau (1989)](@cite rogers1989short).
 
-    The condensation/evaporation and deposition/sublimation tendencies are commonly modeled as **relaxation toward
-    saturation** with timescale `τ_relax`, including a latent-heat (psychrometric/thermal) correction factor; see
-    [Morrison and Grabowski (2008)](@cite Morrison2008novel), Appendix Eq. (A3), and standard cloud microphysics
-    texts such as [Pruppacher and Klett (2010)](@cite pruppacher2010microphysics) or
-    [Rogers and Yau (1989)](@cite rogers1989short).
+For some bulk schemes (e.g. the CloudMicrophysics 1M extension), `liquid` and `ice` may be set to `nothing`
+and used purely as **phase indicators** (warm-phase vs mixed-phase), with any relaxation timescales sourced
+from the scheme's precipitation/category parameters instead.
 
-    For some bulk schemes (e.g. the CloudMicrophysics 1M extension), `liquid` and `ice` may be set to `nothing`
-    and used purely as **phase indicators** (warm-phase vs mixed-phase), with any relaxation timescales sourced
-    from the scheme's precipitation/category parameters instead.
+# Fields
+- `liquid`: Parameters for cloud liquid (contains relaxation timescale `τ_relax`)
+- `ice`: Parameters for cloud ice (contains relaxation timescale `τ_relax`), or `nothing` for warm-phase only
 
-    # Fields
-    - `liquid`: Parameters for cloud liquid (contains relaxation timescale `τ_relax`)
-    - `ice`: Parameters for cloud ice (contains relaxation timescale `τ_relax`), or `nothing` for warm-phase only
+# References
 
-    # References
+* Morrison, H. and Grabowski, W. W. (2008). A novel approach for representing ice
+    microphysics in models: Description and tests using a kinematic framework.
+    J. Atmos. Sci., 65, 1528–1548. https://doi.org/10.1175/2007JAS2491.1
+* Pruppacher, H. R. and Klett, J. D. (2010). Microphysics of Clouds and Precipitation (2nd ed.).
+* Rogers, R. R. and Yau, M. K. (1989). A Short Course in Cloud Physics (3rd ed.).
+"""
+struct NonEquilibriumCloudFormation{L, I}
+    liquid :: L
+    ice :: I
 
-    * Morrison, H. and Grabowski, W. W. (2008). A novel approach for representing ice
-        microphysics in models: Description and tests using a kinematic framework.
-        J. Atmos. Sci., 65, 1528–1548. https://doi.org/10.1175/2007JAS2491.1
-    * Pruppacher, H. R. and Klett, J. D. (2010). Microphysics of Clouds and Precipitation (2nd ed.).
-    * Rogers, R. R. and Yau, M. K. (1989). A Short Course in Cloud Physics (3rd ed.).
-    """
     function NonEquilibriumCloudFormation(liquid, ice=nothing)
         return new{typeof(liquid), typeof(ice)}(liquid, ice)
     end