Changes to the Keywords to get more syntax working

* Switched Link text brackets to be block comments
* Put Code back ticks `` as delimiters
* Added in the angle bracket style of links
* Styled bold and italic separately
* Set the commentLine TreatAsSymbol to be no so that only a # on its own will create a heading
* Updated the Twilight styles to show bold and italic in same colour but with bold / italic styles