add description

Author: katietz

recipe/meta.yaml

@@ -85,6 +85,13 @@ about:
   license_family: BSD
   license_file: LICENSE
   summary: Seamless operability between C++11 and Python
+  description: |
+    pybind11 is a lightweight header-only library that exposes C++ types
+    in Python and vice versa, mainly to create Python bindings of existing
+    C++ code. Its goals and syntax are similar to the excellent Boost.Python
+    library by David Abrahams: to minimize boilerplate code in traditional
+    extension modules by inferring type information using compile-time
+    introspection.
   doc_url: https://pybind11.readthedocs.io/
   dev_url: https://github.com/pybind/pybind11/