clean up old notes

tangara-mainboard/notes-from-r1.txt

@@ -1,18 +0,0 @@
- - double check footprints for small caps
-   - amp 2.2uF (is this in the bom?)
-   - USB IC xtal
-   - battery voltage divider cap
-   - usb IC power (didnt the app notes call for smaller sizes?)
- - fix amp footprint/package discrepancy
- - gpio connector needs NPTH
- - esp32 xtal footprint is too small
- - usb power mosfet has incorrect pinning
- - uart rx/tx swapped
- - add button to EN pin(?)
- - pull IO0 down during boot to flash
-   - use IO2 for SDA instead, then add a BOOT button?
- - need p channel mosfets for most switches :(
- - tie 3v3 reg mode to a gpio
- - replace analog ldo with filtering caps for high noise
- - ESP32 only support to set GPIO0/GPIO1/GPIO3 as mclk signal
- - add real pullups to everything i reckon