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.

scripts/doxygen_to_docstring.py

+#!/usr/bin/env python3
+
+"""Convert doxygen XML output to docstrings that can be used in pybind11"""
+
+from xml.etree import ElementTree
+import copy
+import sys
+
+def make_text(node):
+    """Convert node to plain text"""
+    text = ElementTree.tostring(node, method="text").decode("utf-8")
+    text = text.strip()
+    text = text.rstrip("&").strip()  # No references in python
+    if text.startswith("const "):  # No const in python
+        text = text[7:]
+    return text
+
+def get_description_nodes(node):
+    """Extract the relevant description nodes"""
+
+    brief_description_node = node.find('briefdescription')
+    detailed_description_node = node.find("detaileddescription")
+    new_parameterlist = None
+    paras = detailed_description_node.findall("para")
+    for para in paras:
+        parameterlist = para.find('parameterlist')
+        if parameterlist:
+            new_parameterlist = copy.deepcopy(parameterlist)
+            new_parameterlist.tail = ""
+            if para.text:
+                para.text += parameterlist.tail
+            else:
+                para.text = parameterlist.tail
+            para.remove(parameterlist)
+    return brief_description_node, detailed_description_node, new_parameterlist
+
+def main(filename):
+    root = ElementTree.parse(filename).getroot()
+
+    public_functions = [el for el in root[0].findall('sectiondef') 
+                        if el.attrib['kind']=='public-func'][0]
+
+    for f in public_functions:
+        brief, detailed, params = get_description_nodes(f)
+        print('---------hieronder nieuwe-')
+        print(make_text(f.find('definition')))
+        print('---------dit was de definitie-')
+        if brief:
+            print(make_text(brief))
+        else:
+            print("No brief")
+        if detailed:
+            print(make_text(detailed))
+        else:
+            print("No detailed")
+        if params:
+            print(make_text(params))
+        else:
+            print("No parameterlist")
+
+
+if __name__ == "__main__":
+     filename = sys.argv[1]
+     main(filename)