Sphinx-based documentation added

docs/framework.rst

@@ -0,0 +1,18 @@
+Framework
+=========
+
+.. note::
+
+    For brevity all the code examples in this documentation will assume::
+
+        using namespace units;
+
+.. toctree::
+    :maxdepth: 2
+
+    framework/basic_concepts
+    framework/quantities
+    framework/dimensions
+    framework/units
+    framework/conversions_and_casting
+    framework/text_output