Change ambiguous section titles

Closes #933 and #63

development/cpp/index.rst

@@ -1,5 +1,5 @@
-Developing in C++
-=================
+Engine development 
+==================
 
 .. toctree::
    :maxdepth: 1

learning/scripting/gdscript/gdscript_advanced.rst

@@ -1,7 +1,7 @@
 .. _doc_gdscript_more_efficiently:
 
-GDScript more efficiently
-=========================
+GDScript: An introduction to dynamic languages
+==============================================
 
 About
 -----