Better default-window-size handling for desktop platforms. (#623)

If sapp_desc.width/height is 0:

- on Windows: uses CW_USEDEFAULT for the window size, also centers the window
- on macOS: sets window size to 4/5 of display size (window was already centered before)
- on Linux: sets window size to 4/5 of display size (and centers the window)
- no functional changes on the other platforms.

Some additional changes for fullscreen vs windowed behaviour on Windows:

- stores and restores the window pos and size when switching between windowed and fullscreen
- if the app starts in fullscreen, uses sapp_desc.width/height when switching back to windowed

1 files changed, 2 insertions, 2 deletions

diff --git a/README.md b/README.md
index b18f6cae..2d05a6ee 100644
--- a/README.md
+++ b/README.md
@@ -6,8 +6,8 @@ Simple
 [STB-style](https://github.com/nothings/stb/blob/master/docs/stb_howto.txt)
 cross-platform libraries for C and C++, written in C.
 
-[**See what's new**](https://github.com/floooh/sokol/blob/master/CHANGELOG.md) (**22-Jan-2022** compatibility fix in
-the sokol_audio.h WASAPI backend)
+[**See what's new**](https://github.com/floooh/sokol/blob/master/CHANGELOG.md) (**28-Jan-2022** sokol_app.h: some non-breaking
+default-window-size behaviour changes on desktop platforms)
 
 ## Examples and Related Projects