Create new project directory for pdf-viewer.

Bug: 316458878
Bug: 315917882
Test: N/A
Relnote: N/A

Change-Id: Ie15399b1ae2e0aa05e02ce061e1447affe538039
diff --git a/docs-tip-of-tree/build.gradle b/docs-tip-of-tree/build.gradle
index a43b78d9..c7d7e44 100644
--- a/docs-tip-of-tree/build.gradle
+++ b/docs-tip-of-tree/build.gradle
@@ -292,6 +292,7 @@
     docs(project(":paging:paging-testing"))
     docs(project(":palette:palette"))
     docs(project(":palette:palette-ktx"))
+    docs(project(":pdf:pdf-viewer"))
     docs(project(":percentlayout:percentlayout"))
     docs(project(":preference:preference"))
     docs(project(":preference:preference-ktx"))