Add paragraph-level list formatting support to Google Docs

Enhanced the update_paragraph_style tool to support creating bulleted and
numbered lists with nested indentation levels (0-8). This enables agents to
create well-structured documents that match professional document styles.

Changes:
- Enhanced update_paragraph_style tool with:
  - create_list parameter: Create bulleted (UNORDERED) or numbered (ORDERED) lists
  - list_nesting_level parameter: Support nested list items (0-8 levels)
- Updated create_bullet_list_request helper to accept nesting_level parameter
- Updated documentation in README.md, docs/README.md, and docs/README_NEW.md
- Tool remains in Extended tier as defined in tool_tiers.yaml

This addresses the feature request to expose paragraph-level formatting
operations (named styles, bullets, indentation) that were previously missing
from the character-level modify_doc_text tool.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

gdocs/docs_helpers.py

@@ -279,7 +279,10 @@ def create_insert_image_request(
 
 
 def create_bullet_list_request(
-    start_index: int, end_index: int, list_type: str = "UNORDERED"
+    start_index: int,
+    end_index: int,
+    list_type: str = "UNORDERED",
+    nesting_level: int = None,
 ) -> Dict[str, Any]:
     """
     Create a createParagraphBullets request for Google Docs API.
@@ -288,6 +291,7 @@ def create_bullet_list_request(
         start_index: Start of text range to convert to list
         end_index: End of text range to convert to list
         list_type: Type of list ("UNORDERED" or "ORDERED")
+        nesting_level: Nesting level (0-8, where 0 is top level). If None, uses default behavior.
 
     Returns:
         Dictionary representing the createParagraphBullets request
@@ -298,13 +302,19 @@ def create_bullet_list_request(
         else "NUMBERED_DECIMAL_ALPHA_ROMAN"
     )
 
-    return {
+    request = {
         "createParagraphBullets": {
             "range": {"startIndex": start_index, "endIndex": end_index},
             "bulletPreset": bullet_preset,
         }
     }
 
+    # Add nesting level if specified
+    if nesting_level is not None:
+        request["createParagraphBullets"]["nestingLevel"] = nesting_level
+
+    return request
+
 
 def validate_operation(operation: Dict[str, Any]) -> tuple[bool, str]:
     """