docs: Add documentation for stubgen LIB_PATH option

Author: Doekin

docs/api_cmake.rst

@@ -492,6 +492,14 @@ Nanobind's CMake tooling includes a convenience command to interface with the
           generation. Otherwise, generator expressions should not be used.
           Optional.
 
+      * - ``LIB_PATH``
+        - List of search paths that should be considered when searching for
+          shared libraries. This can be useful when the python module being
+          imported depends on shared libraries that are not in the default
+          search path. The paths are relative to ``CMAKE_CURRENT_BINARY_DIR``
+          for build-time stub generation and relative to
+          ``CMAKE_INSTALL_PREFIX`` for install-time stub generation. Optional.
+
       * - ``DEPENDS``
         - Any targets listed here will be marked as a dependencies. This should
           generally be used to list the target names of one or more prior

docs/typing.rst

@@ -539,8 +539,9 @@ The program has the following command line options:
 
 .. code-block:: text
 
-   usage: python -m nanobind.stubgen [-h] [-o FILE] [-O PATH] [-i PATH] [-m MODULE]
-                                     [-r] [-M FILE] [-P] [-D] [-q]
+   usage: python -m nanobind.stubgen [-h] [-o FILE] [-O PATH] [-i PATH]
+                                     [-L PATH] [-m MODULE] [-r] [-M FILE] [-P]
+                                     [-D] [-q]
 
    Generate stubs for nanobind-based extensions.
 
@@ -550,6 +551,8 @@ The program has the following command line options:
      -O PATH, --output-dir PATH    write generated stubs to the specified directory
      -i PATH, --import PATH        add the directory to the Python import path (can
                                    specify multiple times)
+     -L PATH, --lib-path PATH      add directory to shared library search path (can
+                                   specify multiple times)
      -m MODULE, --module MODULE    generate a stub for the specified module (can
                                    specify multiple times)
      -r, --recursive               recursively process submodules