Update README.md (#148)

According to AI-Thinker officials, the ESP32-2 is a module and not a CPU, so it was changed to the ESP32.

Author: shiinakaze

README.md

@@ -100,7 +100,7 @@ To select the right board use the table below and use the configuration that is
 | Board                           | Image                                                                                               | CPU                     | SRAM   | Flash  | PSRAM | Camera          |             | Site                                                                                                                              |
 |---                              |---                                                                                                  |---                      |---     |---     | ---   |---              |---          |---                                                                                                                                |
 | Espressif ESP32-Wrover CAM      | ![img](assets/boards/esp32-wrover-cam.jpg)                                                          | ESP32                   | 520KB  | 4Mb    | 4MB   | OV2640          |             |                                                                                                                                   |
-| AI-Thinker ESP32-CAM            | ![img](assets/boards/ai-thinker-esp32-cam-ipex.jpg) ![img](assets/boards/ai-thinker-esp32-cam.jpg)  | ESP32-S                 | 520KB  | 4Mb    | 4MB   | OV2640          |             | [https://docs.ai-thinker.com/esp32-cam](https://docs.ai-thinker.com/esp32-cam)                                                    |
+| AI-Thinker ESP32-CAM            | ![img](assets/boards/ai-thinker-esp32-cam-ipex.jpg) ![img](assets/boards/ai-thinker-esp32-cam.jpg)  | ESP32                   | 520KB  | 4Mb    | 4MB   | OV2640          |             | [https://docs.ai-thinker.com/esp32-cam](https://docs.ai-thinker.com/esp32-cam)                                                    |
 | Espressif ESP-EYE               | ![img](assets/boards/espressif-esp-eye.jpg)                                                         | ESP32                   | 520KB  | 4Mb    | 4MB   | OV2640          |             |                                                                                                                                   |
 | Espressif ESP-S3-EYE            | ![img](assets/boards/espressif-esps3-eye.jpg)                                                       | ESP32-S3                | 520KB  | 4Mb    | 4MB   | OV2640          |             | [https://www.espressif.com/en/products/devkits/esp-eye/overview](https://www.espressif.com/en/products/devkits/esp-eye/overview)  |
 | LilyGo camera module            | ![img](assets/boards/lilygo-camera-module.jpg)                                                      | ESP32 Wrover            | 520KB  | 4Mb    | 4MB   | OV2640 / OV5640 |             |                                                                                                                                   |