Hardcoded minimum width and height of 100 px.

Signed-off-by: daukadolt <daulet.amirkhanov.official@gmail.com>

Set Electron window at the center of primaryDisplay if BrowserWindow is not on any displays.

Signed-off-by: daukadolt <daulet.amirkhanov.official@gmail.com>

Set Electron window defaultWidth, defaultHeight to 80% of primary display workArea width, height, respectively.

Signed-off-by: daukadolt <daulet.amirkhanov.official@gmail.com>

Hotfix of a typo that calculates Electron app's default height at first run using primary screen's width, not height.

Signed-off-by: daukadolt <daulet.amirkhanov.official@gmail.com>

Setting defaultWidth/defaultHeight directly without extra variables.
Rounding defaultWidth/defaultHeight.

Signed-off-by: daukadolt <daulet.amirkhanov.official@gmail.com>