What would be the easiest way to allow me to send Shift+Enter to Facebook comment field from my Nexus 10 running Android 4.2 JellyBean, to write multi-paragraph comments?
The built-in keyboard doesn't seem to be able to do this.
The Google keyboard has a "newline" key (looks like an arrow with a 90 degree angle) that appears only when you enter "shift" mode (eg when you want to key in a capital letter). In this mode, the emoji smiley face key changes to a newline key.
On some ROMs, you can set an option to change between the emoji key and the newline (aka enter) key, from within the messaging app settings, under "Soft keyboard type".
I would assume Hacker's Keyboard is capable of sending shift-enters.