Add support for text shadow

[Manikanta Gade]

Is your feature request related to a problem? Please describe.
Add support for text shadow

Describe the solution you'd like

'Sample text with shadow'.text.shadow(offsetX, offsetY, blurRadius, color).make();

or, even better with shadow size variations, like shadowlg(color) and shadowsm(color)

Describe alternatives you've considered
Tried setting .textStyle() for shadow, but is conflicting with .header2() option.

[Alejandro Hipolito (CEO Delikin)]

Done. Hope it helps

[Pawan Kumar]

#129 fixes this