Big documentation and structure updates

- Split math into fdmath package
- Rename waveguide into _2d _3d and _cyl variants
- pdoc-based documentation

pdoc_templates/config.mako

@@ -0,0 +1,46 @@
+<%!
+    # Template configuration. Copy over in your template directory
+    # (used with --template-dir) and adapt as required.
+    html_lang = 'en'
+    show_inherited_members = False
+    extract_module_toc_into_sidebar = True
+    list_class_variables_in_index = True
+    sort_identifiers = True
+    show_type_annotations = True
+
+    # Show collapsed source code block next to each item.
+    # Disabling this can improve rendering speed of large modules.
+    show_source_code = True
+
+    # If set, format links to objects in online source code repository
+    # according to this template. Supported keywords for interpolation
+    # are: commit, path, start_line, end_line.
+    #git_link_template = 'https://github.com/USER/PROJECT/blob/{commit}/{path}#L{start_line}-L{end_line}'
+    #git_link_template = 'https://gitlab.com/USER/PROJECT/blob/{commit}/{path}#L{start_line}-L{end_line}'
+    #git_link_template = 'https://bitbucket.org/USER/PROJECT/src/{commit}/{path}#lines-{start_line}:{end_line}'
+    #git_link_template = 'https://CGIT_HOSTNAME/PROJECT/tree/{path}?id={commit}#n{start-line}'
+    git_link_template = None
+
+    # A prefix to use for every HTML hyperlink in the generated documentation.
+    # No prefix results in all links being relative.
+    link_prefix = ''
+
+    # Enable syntax highlighting for code/source blocks by including Highlight.js
+    syntax_highlighting = True
+
+    # Set the style keyword such as 'atom-one-light' or 'github-gist'
+    #     Options: https://github.com/highlightjs/highlight.js/tree/master/src/styles
+    #     Demo: https://highlightjs.org/static/demo/
+    hljs_style = 'github'
+
+    # If set, insert Google Analytics tracking code. Value is GA
+    # tracking id (UA-XXXXXX-Y).
+    google_analytics = ''
+
+    # If set, render LaTeX math syntax within \(...\) (inline equations),
+    # or within \[...\] or $$...$$ or `.. math::` (block equations)
+    # as nicely-formatted math formulas using MathJax.
+    # Note: in Python docstrings, either all backslashes need to be escaped (\\)
+    # or you need to use raw r-strings.
+    latex_math = True
+%>