v0.4.0

Changelog

de5ab23 Add fallbacks for clock and date widget
ce7e83a Add keycodes file and replace keycodes accordingly
d3df978 Add known configuration values to README
4f4dd19 Add missing godocs
aca4e2c Add support for big clock widgets
d4d3f5f Add time widget with variable format that replaces the clock and date widgets
cbf0bed Add widget documentation
0551d6d Automatically adjust font & image size for button widgets
71d92d6 Bump minimum Go requirement to v1.12
55628fd Don't guess max point size
e765fd7 Drop dev as a global variable
77d9326 Explicitly omit unwanted errors
eedf868 Fix literal keycodes not being translated correctly
bf18f43 Improve horizontal & vertical centering of texts
7a48fb5 Improve label rendering in top widget
6c5ab28 Improve rendering of icon-less buttons
3e0e8cc Improve time widget rendering
a34b336 Let Update return an optional error and handle it during widget updates
c98040d Make image paths relative to the .deck file they're referenced from
7db449e Move font helpers to fonts.go
ffce5de Return an error when time format is empty
3e90f69 Simplify code
add8275 Small changes in README
61809b6 Support background wallpapers (#22)