fixed tx style spacing and char style prefixes

Added double line spacing to the main text paragraph styles:
Text - Standard (tx)
Text - Std No-Indent (tx1)
Text - Standard ALT (atx)
Text - Std No-Indent ALT (atx1)
Text - Computer Type (com)
Text - Computer Type No-Indent (com1)
Text - Narrative (nar)
Text - Narrative No-Indent (nar1)
Text - Dialogue (dia)

Added 2 new character styles: span subscript (sub), span superscript (sup)

Added prefix "span" to all character styles to help sort them

Added color to all character styles to give them visual distinction