Add text formatting support

[ambrosiogabe]

You should be able to format text inline with custom colors etc. Something like:

This is some text with <color = "blue">BLUE</color> text!!
This is some text with <i>ITALIC</i> text!
And this is some text with <bold><italic><color="yellow">multiple styles</color></italic></bold> on the text!!

Note that the formatting should support HTML style groups with the following:

• Color group:
  • <color = CSS_STYLE_COLOR></color>
• Italic group:
  • <i></i>
  • <italic></italic>
  • <italics></italics> # TODO: Should this be supported??
• Bold group:
  • <b></b>
  • <bold></bold>
• Underline group:
  • <underline></underline>
• Strikethrough group:
  • <strikethrough></strikethrough>

Additional notes:

For group formatting (these things <></>):

• It is case-insensitive
  • <b> == <B>
  • <bOlD> == <bold>
• It is whitespace-insensitive (except for newlines)
  • < bold> == <bold> == < bold >
  • < bol
    d> != < bold>
  • All group openings must have a matching closing group
    • <bold><italic></italic> INVALID: No matching \</bold\>
  • Group openings/closing must respect order
    • <bold><italic> This is italic and bold</italic>, but this is just bold</bold> and this is not formatted
  • Group closing order must be the inverse of opening order
    • <bold><italic></italic></bold> OK: Close order matches open order bold -> italic <-> italic <- bold
    • <bold><italic></bold></italic> NOT OK: Close order is unmatched bold -> italic <-> bold <- italic

Any additional formatting rules will be written down here for documentation purposes. They will also be documented as part of this repositories documentation as they get added.