Pico UART-USB bridge v4.2

• pico-sdk: update to v1.5.1
• uart-bridge: restore clock speed
• github: bump upload-artifact to v4
• github: bump checkout to v4

Pico UART-USB bridge v4.1

• Switch from memcpy to memmove when copying within buffers

Pico UART-USB bridge v4.0

• uart-bridge: avoid CR/LF conversion
• Switch UART0 to GPIO 16 (TX) & GPIO 17 (RX)
• uart-bridge: add UART RX interrupts
• Increase buffers and improve USB descriptors
• Code cleanup

Pico UART-USB bridge v3.1

• github: improve CI
• pico-sdk: update to 1.4.0
• usb-descriptors: use flash ID as USB serial

Pico UART-USB bridge v3.0

• uart-bridge: bump clock to 250 MHz
• uart-bridge: increase BUFFER_SIZE
• build.sh: improve script
• github: update CI workflow
• pico-sdk: update v1.3.0
• uart-bridge: usb_read_bytes: fix usb_buffer access
• github: force Ubuntu 20.04

Pico UART-USB bridge v2.1

• Refactor code.
• Remove unused variables.
• Automatically checkout pico-sdk from build.sh if neded.
• Improve usb_write_bytes().
• Add Github CI.

Pico UART-USB bridge v2.0

Now exposes both UART controllers as two independent USB CDC devices.

Pico UART-USB bridge v1.1

Small bug fixes.

Pico UART-USB bridge v1.0

First release of Raspberry Pi Pico UART-USB bridge.