Add doc about litgen in the FAQ (#780)

docs/faq.rst

@@ -398,6 +398,19 @@ build system compatible with another tool that is sufficiently
 feature-complete, then please file an issue and I am happy to reference it in
 the documentation.
 
+Are there tools to generate nanobind bindings automatically?
+------------------------------------------------------------
+
+`litgen <https://pthom.github.io/litgen>`__ is an automatic Python bindings 
+generator compatible with both pybind11 and nanobind, designed to create 
+documented and easily discoverable bindings. 
+It reproduces header documentation directly in the bindings, making the 
+generated API intuitive and well-documented for Python users. 
+Powered by srcML (srcml.org), a high-performance, multi-language parsing tool, 
+litgen takes a developer-centric approach. 
+The C++ API to be exposed to Python must be C++14 compatible, although the 
+implementation can leverage more modern C++ features.
+
 How to cite this project?
 -------------------------