Add missing line continuations to README.md

Bug: b/280222419
Change-Id: Ia213a239f5060538960344748c5abe4ad53e2ce6
diff --git a/README.md b/README.md
index e294028..0a085c1 100644
--- a/README.md
+++ b/README.md
@@ -90,9 +90,9 @@
 Release mode build:
 
     $ java -cp build/libs/r8.jar com.android.tools.r8.D8
-           --release
+           --release \
            --min-api <min-api> \
-           --output out
+           --output out \
            --lib <android.jar/rt.jar> \
            input.jar