SPI lib: fixed bugs discovered by JKT

Update standby examples and add implementation notes.

fix the adc trigger settings

added all examples to platformio

to keep platformio projects in sync with the examples folders, I added missing ones in alphabetical order.

Add warning message if WCH-LinkE is detected in ARM mode

Make top comment section match project.

Make it so minichlink will automatically try to get found if you have and have linked a ch32v003fun repository

Update with nulled printf (to prevent warnings on non-printf projects) and undestructively add interrupt nesting to WS2812B driver.

Fix for UART fractional BRR caclulation

 * Allow interrupt preemption in WS2812B driver.
 * Add simple driver for ws2812b's.

tim2_encoder example based on tim2_pwm_remap

Add #ifdef support for CH3/CH4 in tim2_pwm example

Avoid bricking CH32V003J4M6 - For #219

-Implement CH3 and CH4 optionally via #define
-By default only CH1 and CH2 are enabled.
-Channels 3 and 4 can be enabled by uncommenting the appropriate line
-Choose whether default of PWM pins is HIGH (0xff) or LOW (0x00)

NOTES:
-Channel 3 is on a different port (GPIOC) which will be enabled if
needed.

-Channel 4 is on the NRST pin so not usable unless you use `minichlink -d`
to disable the NRST function so the pin can be used as a GPIO

-If your board has a bypass capacitor on PD7 for a reset button the
waveforms observed on CH4 will not be nice square waves.