Include dir only if present. (#237)

Author: kattni

src/beeware_docs_tools/md_tempdir.py

@@ -68,23 +68,22 @@ def save_config(project_path, temp_md_path, config, language="en"):
 
     base_path = config["markdown_extensions"]["pymdownx.snippets"].get("base_path", [])
 
-    contribution_root = config["extra"].get(
-        "contribution_guide_root", "how-to/contribute"
-    )
+    contribution_root = config["extra"].get("contribution_guide_root")
 
     if language != "en":
         shared_content_path = temp_md_path.resolve() / f"shared_content/{language}"
-        local_docs_path = temp_md_path.resolve() / language / contribution_root
+        if contribution_root:
+            local_docs_path = temp_md_path.resolve() / language / contribution_root
     else:
         shared_content_path = (Path(__file__).parent / "shared_content/en").resolve()
-        local_docs_path = (project_path / "docs/en" / contribution_root).resolve()
+        if contribution_root:
+            local_docs_path = (project_path / "docs/en" / contribution_root).resolve()
 
     base_path.append(str(shared_content_path))
     config["markdown_extensions"]["pymdownx.snippets"]["base_path"] = base_path
-    config["plugins"]["macros"]["include_dir"] = [
-        str(shared_content_path),
-        str(local_docs_path),
-    ]
+    config["plugins"]["macros"]["include_dir"] = [str(shared_content_path)]
+    if contribution_root:
+        config["plugins"]["macros"]["include_dir"].append(str(local_docs_path))
 
     with (temp_md_path / "config.yml").open("w", encoding="utf-8") as config_f:
         yaml.dump(config, config_f)