Update README.md

Update version to `0.7.1.15`

Fix window sizing when launching app first time

Merge pull request U-C-S#52 from U-C-S/dev/restructure-mvvm-ig

The Long-waited MVVM implementation

Update version to `0.6.3.12`

Improvements to `Models/Browser.cs`

Various UI tweaks

- Max view of 5 browsers at once [ref. U-C-S#25]
- Use DynamicScrollViewer. it auto-hides.
- Hide BrowserIconBtn's context menu btn temp
- ....others

A Minor Update focusing on Single-Instancing, Minimizing to Tray

See U-C-S#28 for changelog

See U-C-S#17 (comment) for changelog