add changelog, increase version for release

Author: hathach

changelog.md

@@ -0,0 +1,39 @@
+# Adafruit TinyUSB Arduino Library Changelog
+
+## 0.8.0 - 2019.12.30
+
+- Correct USB BCD version to 2.1 for webUSB
+- Migrate CI from travis to github actions
+
+## 0.7.1 - 2019.10.12
+
+- Fixed MIDI build failed since it is under development
+
+## 0.7.0 - 2019.10.09
+
+- Added MIDI virtual wires/plugs
+
+## 0.6.0 - 2019.08.05
+
+- Added webUSB support with 2 example: webusb-serial, webusb-rgb
+- Alligned mouse examples, added newer hid in/out example from main repo, added new composite example for ramdisk and hid in/out. PR #19 thanks to @PTS93
+
+## 0.5.0 - 2019.07.17
+
+- Added travis build
+- Fixed msc setID
+- Added itfnum to internal API getDescriptor() 
+- Added MIDI support
+  - Added midi_test example
+  - Added pizza box dj example for cplayground express
+- Mass Storage
+  - Added msc_sdfat, msc dual lun (external flash + sd card)  example  
+  - Updated msc example to use new SPIFlash 3.x API
+  - Update msc example to print root contents
+- HID
+  - Added hid_mouse, hid_keyboard
+  - Added hid_composite_joy_featherwing
+- Added Composite: mouse_ramdisk, mouse_external_flash example
+
+## 0.0.1 Initial Release
+

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit TinyUSB Library
-version=0.7.1
+version=0.8.0
 author=Adafruit
 maintainer=Adafruit <info@adafruit.com>
 sentence=TinyUSB library for Arduino