update changelog and readme, ready to relase 0.2.12

Author: hathach

README.md

@@ -6,6 +6,7 @@ This is a CDC/DFU/UF2 bootloader for nRF52 boards.
 
 - [Adafruit Feather nRF52832](https://www.adafruit.com/product/3406)
 - [Adafruit Feather nRF52840 Express](https://www.adafruit.com/product/4062)
+- [Adafruit Circuit Playground Bluefruit](https://www.adafruit.com/product/4333)
 - Adafruit Metro nRF52840 Express
 - [Electronut Labs Papyr](https://docs.electronut.in/papyr/)
 - MakerDiary MDK nRF52840 USB Dongle

changelog.md

@@ -1,5 +1,12 @@
 # Adafruit nRF52 Bootloader Changelog
 
+## 0.2.12 - 2019.08.22
+
+- Fixed block alignment bug also in dfu_sd_image_validate (single & dual banks), PR #71 thanks to @fanoush
+- Added new board: Adafruit Circuit Playground Bluefruit
+- Added new board: Adafruit ItsyBitsy nRF52840 Express (WIP)
+- Fixed bug in __DOSTIME__ macro, PR #75 thanks to @henrygab
+
 ## 0.2.11
 
 - Fixed various FAT issues, thanks to @henrygab