Updated Doxygen docs

Doxyfile

@@ -44,7 +44,7 @@ PROJECT_NUMBER         = 0.3.7
 # for a project that appears at the top of each page and should give viewer a
 # quick idea about the purpose of the project. Keep the description short.
 
-PROJECT_BRIEF          = C++ UML diagram generator based on Clang
+PROJECT_BRIEF          = C++ to UML diagram generator based on Clang
 
 # With the PROJECT_LOGO tag one can specify a logo or an icon that is included
 # in the documentation. The maximum height of the logo should not exceed 55
@@ -781,7 +781,7 @@ FILE_VERSION_FILTER    =
 # DoxygenLayout.xml, doxygen will parse it automatically even if the LAYOUT_FILE
 # tag is left empty.
 
-LAYOUT_FILE            =
+LAYOUT_FILE            = docs/doxygen/layout-clang-uml.xml
 
 # The CITE_BIB_FILES tag can be used to specify one or more bib files containing
 # the reference definitions. This must be a list of .bib files. The .bib
@@ -1013,7 +1013,9 @@ EXAMPLE_RECURSIVE      = NO
 # that contain images that are to be included in the documentation (see the
 # \image command).
 
-IMAGE_PATH             = docs/diagrams
+IMAGE_PATH             = docs/img
+IMAGE_PATH             += docs/diagrams
+IMAGE_PATH             += docs/test_cases
 
 # The INPUT_FILTER tag can be used to specify a program that doxygen should
 # invoke to filter for each input file. Doxygen will invoke the filter program
@@ -1305,9 +1307,9 @@ HTML_EXTRA_FILES       = thirdparty/doxygen-awesome-css/doxygen-awesome-interact
 HTML_EXTRA_FILES       += thirdparty/doxygen-awesome-css/doxygen-awesome-paragraph-link.js
 HTML_EXTRA_FILES       += thirdparty/doxygen-awesome-css/doxygen-awesome-fragment-copy-button.js
 HTML_EXTRA_FILES       += thirdparty/doxygen-awesome-css/doxygen-awesome-tabs.js
-HTML_EXTRA_FILES       += CONTRIBUTING.md
 HTML_EXTRA_FILES       += docs/doxygen/highlight.min.js
-HTML_EXTRA_FILES       += docs/doxygen/solarized-light.min.css
+HTML_EXTRA_FILES       += docs/doxygen/github.min.css
+HTML_EXTRA_FILES       += docs/img/github-mark.svg
 
 # The HTML_COLORSTYLE_HUE tag controls the color of the HTML output. Doxygen
 # will adjust the colors in the style sheet and background images according to