ui: Add Pivot tables design doc to toc am: 07ba9e21ca am: d37f93ce87 am: 70045dcb30 am: bf04b9c086
ui: Add Pivot tables design doc to toc am: 07ba9e21ca am: d37f93ce87 am: 70045dcb30 am: bf04b9c086

Original change: https://android-review.googlesource.com/c/platform/external/perfetto/+/1831613

Change-Id: I62af0d5eda0ed3ea427af1aebeec4cdfb7082c03

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto