Fix dummy data in the line charts on the line chart docs

[aieaee]

There is a small error in the dummy data for the second data series on the line charts docs page: https://polaris-viz.shopify.io/?path=/docs/default-charts-linechart--default

The first two keys are swapped, so the dotted line says "March 2, March 1, March 3"

Also the lines for March 6 and 7 are reversed

This is also the case for the following charts:

• Hide X Axis Labels
• No Overflow Style
• No Label Wrapping

[krystalcampioni]

Already fixed