message: refactor(app): add explanation and link to cal card
  This will be an ever-present reminder of what calibration is that lives
  in the calibration card.
diff: @@ -22,6 +22,9 @@ import { useTrackEvent } from '../../analytics'
  import {
  useInterval,
  Card,
  + Box,
  + BORDER_SOLID_LIGHT,
  + DISPLAY_INLINE,
  ALIGN_BASELINE,
  FONT_SIZE_BODY_1,
  Link,
  @@ -56,6 +59,12 @@ const EVENT_CALIBRATION_DOWNLOADED = 'calibrationDataDownloaded'
  const TITLE = 'Robot Calibration'
  const DOWNLOAD_CALIBRATION = 'Download your calibration data'
  +const CAL_EXPLANATION =
  + 'Your OT-2 moves pipettes around in 3D space based on its calibration.'
  +const LEARN_MORE = 'Learn more'
  +const CAL_EXPLANATION_SUFFIX = 'about how calibration works on the OT-2.'
  +const CAL_ARTICLE_URL =
  + 'https://support.opentrons.com/en/articles/3499692-how-calibration-works-on-the-ot-2'
  const attachedPipetteCalPresent: (
  pipettes: AttachedPipettesByMount,
  @@ -189,6 +198,24 @@ export function CalibrationCard(props: Props): React.Node {
  {DOWNLOAD_CALIBRATION}
  </Link>
  </Flex>
  + <Box
  + borderBottom={BORDER_SOLID_LIGHT}
  + fontSize={FONT_SIZE_BODY_1}
  + padding={SPACING_3}
  + >
  + <Text display={DISPLAY_INLINE}>{CAL_EXPLANATION}</Text>
  + &nbsp;
  + <Link
  + color={C_BLUE}
  + display={DISPLAY_INLINE}
  + external
  + href={CAL_ARTICLE_URL}
  + >
  + {LEARN_MORE}
  + </Link>
  + &nbsp;
  + <Text display={DISPLAY_INLINE}>{CAL_EXPLANATION_SUFFIX}</Text>
  + </Box>
  <DeckCalibrationControl
  robotName={robotName}
  disabledReason={buttonDisabledReason}
  