Group documentation pages

All documentation pages are made subpages of a page Documentation, this
helps browse documentation not directly tied to source code.

Signed-off-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>

docs/doxygen/CMakeLists.txt

@@ -34,7 +34,6 @@ if(DOXYGEN_FOUND)
     endif()
     set(DOXYGEN_PROJECT_LOGO ${CMAKE_CURRENT_SOURCE_DIR}/pyrogenesis.png)
     set(DOXYGEN_TAB_SIZE 4)
-    set(DOXYGEN_USE_MDFILE_AS_MAINPAGE ${CMAKE_CURRENT_SOURCE_DIR}/Main-Page.md)
     set(DOXYGEN_EXCLUDE_PATTERNS */.svn* */tests/test_*)
     set(DOXYGEN_INCLUDE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../source)
     set(DOXYGEN_EXAMPLE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../source)
@@ -57,7 +56,7 @@ if(DOXYGEN_FOUND)
 
     doxygen_add_docs(${CMAKE_PROJECT_NAME}
              ${CMAKE_CURRENT_SOURCE_DIR}/../../source
-             ${CMAKE_CURRENT_SOURCE_DIR}/Main-Page.md
+             ${CMAKE_CURRENT_SOURCE_DIR}/mainpage.dox
              ${CMAKE_CURRENT_SOURCE_DIR}/../../LICENSE.md
             ALL)
 else()

docs/doxygen/Main-Page.md

@@ -1,14 +0,0 @@
-# Pyrogenesis
-
-The Pyrogenesis Engine is specifically designed for flexibility and ease of modification.
-This document should help all that want to contribute their Work to this Engine.
-
-## Thirdparty
-
-- [Vulkan Memory Allocator](https://gpuopen-librariesandsdks.github.io/VulkanMemoryAllocator/html/)
-- [tinygettext](https://github.com/tinygettext/tinygettext)
-- [doxygen-awesome-css](https://github.com/jothepro/doxygen-awesome-css)
-
-## License
-
-[0 A.D. Licensing Details](../../LICENSE.md)

docs/doxygen/mainpage.dox

@@ -0,0 +1,29 @@
+/*!
+@mainpage
+
+<h1>Pyrogenesis</h1>
+
+<p>The Pyrogenesis Engine is specifically designed for flexibility and ease of modification.</p>
+<p>This document should help all that want to contribute their Work to this Engine.</p>
+
+<h2>Thirdparty</h2>
+- <a href="https://gpuopen-librariesandsdks.github.io/VulkanMemoryAllocator/html/">Vulkan Memory Allocator</a>
+- <a href="https://github.com/tinygettext/tinygettext">tinygettext</a>
+- <a href="https://github.com/jothepro/doxygen-awesome-css">doxygen-awesome-css</a>
+
+<h2>License</h2>
+
+@link ../../LICENSE.md 0 A.D. Licensing Details
+
+*/
+
+
+/*!
+@page docs Documentation
+
+<h2>Components</h2>
+
+- @subpage writing-components
+- @subpage serialization
+
+*/