docs(mapping/compactification): added compactification documentation

src/include/serif/mapping/compactification/variation.hpp

@@ -1,16 +1,35 @@
 #pragma once
 
+/**
+ * @file variation.hpp
+ * @author Emily M. Boudreaux
+ *
+ * @brief File containing the structures for the variation of the compactification mapping.
+ */
+
 #include "mfem/linalg/vector.hpp"
 #include "mfem/linalg/densemat.hpp"
 
 namespace serif::mapping::compactification {
+    /**
+     * @struct ExteriorMapDirection
+     *
+     * @brief Structure representing the direction of the variation in the exterior domain mapping.
+     * This includes the variation of the displaced position and the variation of the displacement Jacobian.
+     */
     struct ExteriorMapDirection {
-        const mfem::Vector &displaced_position_variation;
-        const mfem::DenseMatrix &displacement_jacobian_variation;
+        const mfem::Vector &displaced_position_variation;           ///< Variation of the position in displaced space.
+        const mfem::DenseMatrix &displacement_jacobian_variation;  ///< Variation of the Jacobian of the displacement mapping.
     };
 
+    /**
+     * @struct ExteriorMapVariation
+     *
+     * @brief Structure representing the variation of the exterior domain mapping.
+     * This includes the variation of the physical position and the variation of the mapping Jacobian.
+     */
     struct ExteriorMapVariation {
-        mfem::Vector physical_position_variation;
-        mfem::DenseMatrix mapping_jacobian_variation;
+        mfem::Vector physical_position_variation;      ///< Variation of the position in physical space.
+        mfem::DenseMatrix mapping_jacobian_variation;  ///< Variation of the Jacobian of the mapping.
     };
 }