Rework the Optimizing for size page

- Order options from most important to least important.
- Give estimates on space saved for each option.
- Clarify the benefits of stripping binaries.
- Link to the Godot build options generator in the Overriding build
  options link instead of linking it in the Optimizing for size page.

(cherry picked from commit 8a95663768)

development/cpp/using_cpp_profilers.rst

@@ -1,3 +1,5 @@
+.. _doc_using_cpp_profilers:
+
 Using C++ profilers
 ===================