AQL syntax highlighter

[Simran-B]

• Custom Pygments lexer to properly colorize AQL queries
  • Works with most queries, but there are some corner cases to avoid (e.g. variables called keep, prune, search, and to, comments between WITH COUNT INTO or a function name and the opening parenthesis).
  • The highlighter is not used for @EXAMPLE_AQL (not done using Jekyll/Rouge)
  • Go implementation: https://github.com/Simran-B/chroma/tree/aql
• Tweaks to the style configuration
• Replace ```js fenced code blocks with ```aql for AQL queries and execution plans