chore: regens API reference docs (#889)

diff --git a/docs/dyn/books_v1.onboarding.html b/docs/dyn/books_v1.onboarding.html
index b21aee3..e0c03cd 100644
--- a/docs/dyn/books_v1.onboarding.html
+++ b/docs/dyn/books_v1.onboarding.html
@@ -231,7 +231,7 @@
             "height": "A String", # Height or length of this volume (in cm).
           },
           "previewLink": "A String", # URL to preview this volume on the Google Books site.
-          "contentVersion": "A String", # An identifier for the version of the volume content (text & images). (In LITE projection)
+          "contentVersion": "A String", # An identifier for the version of the volume content (text & images). (In LITE projection)
           "industryIdentifiers": [ # Industry standard identifiers for this volume.
             {
               "identifier": "A String", # Industry specific volume identifier.