🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Author: gcf-owl-bot[bot]

docs/conf.py

@@ -76,8 +76,8 @@
 # The encoding of source files.
 # source_encoding = 'utf-8-sig'
 
-# The master toctree document.
-master_doc = "index"
+# The root toctree document.
+root_doc = "index"
 
 # General information about the project.
 project = "google-cloud-debugger-client"
@@ -280,7 +280,7 @@
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
     (
-        master_doc,
+        root_doc,
         "google-cloud-debugger-client.tex",
         "google-cloud-debugger-client Documentation",
         author,
@@ -315,7 +315,7 @@
 # (source start file, name, description, authors, manual section).
 man_pages = [
     (
-        master_doc,
+        root_doc,
         "google-cloud-debugger-client",
         "google-cloud-debugger-client Documentation",
         [author],
@@ -334,7 +334,7 @@
 #  dir menu entry, description, category)
 texinfo_documents = [
     (
-        master_doc,
+        root_doc,
         "google-cloud-debugger-client",
         "google-cloud-debugger-client Documentation",
         author,