Update readme.md

Fix typo

usermods/sd_card/readme.md

@@ -20,7 +20,7 @@
   | `pinSourceSelect` | GPIO that is connected to SD's `SS`(source select) / `CS`(chip select)                           | 16      |
   | `pinSourceClock`  | GPIO that is connected to SD's `SCLK` (source clock) / `CLK`(clock)                              | 14      |
   | `pinPoci`         | GPIO that is connected to SD's `POCI`<sup>☨</sup> (Peripheral-Out-Ctrl-In) / `MISO` (deprecated) | 36      |
-  | `pinPico`         | GPIO that is connected to SD's `PICO`<sup>☨</sup> (Peripheral-In-Ctrl-Out) / `MOSI` (deprecated) | 14      |
+  | `pinPico`         | GPIO that is connected to SD's `PICO`<sup>☨</sup> (Peripheral-In-Ctrl-Out) / `MOSI` (deprecated) | 15      |
   | `sdEnable`        | Enable to read data from the SD-card                                                             | true    |
 
   <sup>☨</sup><sub>Following new naming convention of [OSHWA](https://www.oshwa.org/a-resolution-to-redefine-spi-signal-names/)</sub>
@@ -31,4 +31,4 @@
 -  checks if the specified file is available on the SD card
    ```cpp
    bool file_onSD(const char *filepath) {...}
-   ```
+   ```