add callout for winderoo esp32 (#6)

instructions/bom-requirements.md

@@ -27,10 +27,15 @@ This means that you'll be able to construct a 3-watch winder. Remember that the
 ### Total cost of required Parts
 - **$40.00 (February 2023)**
 
+> [!NOTE]
 > The following tables contains affiliate links to Aliexpress; **you do not pay an inflated price because of this.** Should you decide to use another supplier, please ensure that you cross-reference this table and buy identical components. 
-
+>
 > While most of these components are standardized, I will not be able to assist you if you purchase your components from a separate supplier, as the winder was designed around the components (as supplied) beneath.
 
+> [!CAUTION]
+> If you're planning a [Widneroo](https://github.com/mwood77/winderoo) build, do not purchase a Raspberry Pi Pico. Purchase an ESP32 instead to save some money and avoid future headaches. You can find a link to purchase an ESP32 in [Winderoo's Bill of Materials](https://github.com/mwood77/winderoo/blob/pwm-motor-control/docs/bom-requirements.md#total-cost-of-required-parts).
+
+
 |     |  Quantity per Order | Link / Part Name                                                             |  Comments                                              |  Cost Incl. Shipping |
 | :-: | :------------: | :-------------------------------------------------------------------------------: | :-------------------------------------------------------------------: |:-----:|
 | 🔲 | 1               | [Raspberry Pi Pico](https://www.raspberrypi.com/products/raspberry-pi-pico/)      |    Wireless: **NO** & GPIO Headers: **NO**                                                                   | $5.00 |