Improve documentation related to inheritance. (#1676)

* Adds section to the reference.
* Adds section to advanced classes page describing how to use `get_overload`.
diff --git a/docs/faq.rst b/docs/faq.rst
index 99a12cb..93ccf10 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -39,6 +39,8 @@
 
     cmake -DPYTHON_EXECUTABLE:FILEPATH=<path-to-python-executable> .
 
+.. _faq_reference_arguments:
+
 Limitations involving reference arguments
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