Add 2021 Corolla Hybrid to Supported Cars in README.md (#2229)

Followup to https://github.com/commaai/openpilot/pull/1845 which added FW/FPv2 from a *2021* Corolla Hybrid.

User confirmed again their vehicle is a 2021 Corolla Hybrid recently: https://discordapp.com/channels/469524606043160576/524327905937850394/759264135812349962

By the way, the ICE-only 2021 Corolla has still not been confirmed or tried against and no mention has been found in Discord about successful attempts or failures regarding that model and model year.
old-commit-hash: 0bd66a40d8

README.md

@@ -101,7 +101,7 @@ Supported Cars
 | Toyota    | Corolla 2017-19               | All               | Stock<sup>3</sup>| 20mph<sup>1</sup>  | 0mph              |
 | Toyota    | Corolla 2020                  | All               | openpilot        | 0mph               | 0mph              |
 | Toyota    | Corolla Hatchback 2019-20     | All               | openpilot        | 0mph               | 0mph              |
-| Toyota    | Corolla Hybrid 2020           | All               | openpilot        | 0mph               | 0mph              |
+| Toyota    | Corolla Hybrid 2020-21        | All               | openpilot        | 0mph               | 0mph              |
 | Toyota    | Highlander 2017-19            | All               | Stock<sup>3</sup>| 0mph               | 0mph              |
 | Toyota    | Highlander 2020               | All               | openpilot        | 0mph               | 0mph              |
 | Toyota    | Highlander Hybrid 2017-19     | All               | Stock<sup>3</sup>| 0mph               | 0mph              |