Draft: Add sphinx documentation

The mechanism for building docs was copied from EveryBeam; it parses both Doxygen documentation and python documentation into a sphinx page.

cpp/settings.h

@@ -92,11 +92,13 @@ enum class MultiscaleShape {
   kGaussianShape
 };
 
+/**
+ * Class to collect and set (Radler) deconvolution related settings.
+ */
 struct Settings {
   /**
+   * Top-level settings that are also used outside deconvolution
    * @{
-   * Settings that are duplicates from top level settings, and also used outside
-   * deconvolution.
    */
   size_t trimmed_image_width = 0;
   size_t trimmed_image_height = 0;
@@ -175,10 +177,14 @@ struct Settings {
    * @brief Sigma value for automatically creating and applying mask images.
    *
    * If set, Radler performs these steps:
-   * # Radler starts cleaning towards a threshold of the given sigma value.
-   * # Once the sigma level is reached, Radler generates a mask using the
+   *
+   *   * Radler starts cleaning towards a threshold of the given sigma value.
+   *
+   *   * Once the sigma level is reached, Radler generates a mask using the
    * positions and (when using multi-scale cleaning) scale of each component.
-   * # Cleaning then continues until the final threshold value, as set using the
+   *
+   *   * Cleaning then continues until the final threshold value, as set using
+   * the
    * @ref threshold or @ref auto_threshold_sigma values. During this final
    * deconvolution stage, the generated mask constrains the cleaning.
    *
@@ -342,9 +348,9 @@ struct Settings {
   /** @} */
 
   /**
-   * @{
    * These deconvolution settings are algorithm-specific. For each algorithm
    * type, a single struct holds all algorithm-specific settings for that type.
+   * @{
    */
 
   AlgorithmType algorithm_type = AlgorithmType::kGenericClean;