Pyxel

- Enabled to open a resource file by drop in Pyxel Editor
- Renamed the constants for the mouse buttons
- Added gamepad support
- Changed gamepad available for Example 2
- Fixed the crash bug when the window is minimized
- Modified the code of Example 6
- Added the refimg property to the Tilemap class
- Removed the img argument from the bltm API
- Updated the screenshot of Example 3

- Enabled to import png by drop in Image Editor
- Fixed the crash bug caused by unsupported keys
- Enabled to play the piano with mouse in Sound Editor
- Enabled to repeat undo/redo shortcuts

- Fixed the color pick bug of Image Editor
- Changed the focus UI of Image Editor

- Fixed the bug where Pyxel Editor cursor malfunctions
- Added new API descriptions to Example 3
- Updated the screenshot of Example 3
- Change to not add unnecessary undo history of the editors
- Added the setting files for Pipenv
- Modified the cursor design of Image/Tilemap Editor
- Enabled to change the focus size of Tilemap Editor
- Added the link to the subreddit in the manuals
- Changed to exports all constants for keys before init is called
- Added the contribution section to the manuals

- Fixed the tilemap to allow the tiles of 256 or higher
- Updated the screenshots of Pyxel Editor
- Fixed the cursor movement of Sound/Music Editor
- Changed the caption of Example 2
- Renamed Example 6
- Fixed the error when saving long animated GIF

- Added the .pyxel file to the install example script