Fix a small typo in README.md
Fix a small typo in README.md

Change-Id: I746c4a6ce31a0997ba7fe5495673cce3cf9268c3
ORIGINAL_AUTHOR=Thai Duong <thaidn@google.com>

GitOrigin-RevId: 96f59160d45ca3aba9b23061ddf7df1aca862376

google/tink,google/tink,google/tink,google/tink,google/tink,google/tink,google/tink,google/tink