Docs: Contributing changes (#17551)

A few minor changes for contribution:

1) Updating link to say "Contributing" rather than "Developer's guide"
2) Minor changes after going through the contributing documentation
page.

docs/api_reference/create_api_rst.py

@@ -14,7 +14,6 @@ from pydantic import BaseModel
 ROOT_DIR = Path(__file__).parents[2].absolute()
 HERE = Path(__file__).parent
 
-
 ClassKind = Literal["TypedDict", "Regular", "Pydantic", "enum"]
 
 
@@ -323,30 +322,52 @@ def _package_dir(package_name: str = "langchain") -> Path:
 
 
 def _get_package_version(package_dir: Path) -> str:
-    with open(package_dir.parent / "pyproject.toml", "r") as f:
-        pyproject = toml.load(f)
+    """Return the version of the package."""
+    try:
+        with open(package_dir.parent / "pyproject.toml", "r") as f:
+            pyproject = toml.load(f)
+    except FileNotFoundError as e:
+        print(
+            f"pyproject.toml not found in {package_dir.parent}.\n"
+            "You are either attempting to build a directory which is not a package or "
+            "the package is missing a pyproject.toml file which should be added."
+            "Aborting the build."
+        )
+        exit(1)
     return pyproject["tool"]["poetry"]["version"]
 
 
-def _out_file_path(package_name: str = "langchain") -> Path:
+def _out_file_path(package_name: str) -> Path:
     """Return the path to the file containing the documentation."""
     return HERE / f"{package_name.replace('-', '_')}_api_reference.rst"
 
 
-def _doc_first_line(package_name: str = "langchain") -> str:
+def _doc_first_line(package_name: str) -> str:
     """Return the path to the file containing the documentation."""
     return f".. {package_name.replace('-', '_')}_api_reference:\n\n"
 
 
 def main() -> None:
     """Generate the api_reference.rst file for each package."""
+    print("Starting to build API reference files.")
     for dir in os.listdir(ROOT_DIR / "libs"):
+        # Skip any hidden directories
+        # Some of these could be present by mistake in the code base
+        # e.g., .pytest_cache from running tests from the wrong location.
+        if not dir.startswith("."):
+            print("Skipping dir:", dir)
+            continue
+
         if dir in ("cli", "partners"):
             continue
         else:
+            print("Building package:", dir)
             _build_rst_file(package_name=dir)
-    for dir in os.listdir(ROOT_DIR / "libs" / "partners"):
+    partner_packages = os.listdir(ROOT_DIR / "libs" / "partners")
+    print("Building partner packages:", partner_packages)
+    for dir in partner_packages:
         _build_rst_file(package_name=dir)
+    print("API reference files built.")
 
 
 if __name__ == "__main__":