Update public/index.html, public/previewImages/placeholder.png, public/previewImages/exit.png, public/previewImages/robot.png

Test for menu bar with placeholder image

See merge request !86

Update public/index.html

See merge request !84

Update public/index.html

See merge request geovistoogsi/ar!83

Update public/index.html

See merge request geovistoogsi/ar!82

Update public/index.html

See merge request geovistoogsi/ar!81

Update public/index.html

See merge request geovistoogsi/ar!80

Update public/index.html

See merge request geovistoogsi/ar!79

Update public/index.html

See merge request !78

Update public/index.html

See merge request !77

Update public/index.html

See merge request !76

Update public/index.html

See merge request !75

Update public/index.html

See merge request !74

Update public/index.html

See merge request !73

Update public/index.html

See merge request !72

Update public/index.html

See merge request geovistoogsi/ar!71

Update public/index.html

See merge request geovistoogsi/ar!70

Update public/index.html

See merge request !69

Update public/index.html

See merge request !68

Update public/index.html

See merge request geovistoogsi/ar!67

Update public/index.html

See merge request geovistoogsi/ar!66