Feature/syntaxhighlighting (#9)

* wip code highlighting of lines

* Implements gutter component

* WIP: Profiler with gutter

* cleaned up highlight code

* Removes before content for gutter styling

* Styles gutter

* Add correct Profiler code content

* Adds color variable for gutter gray

* refactor code component width gutter and diffing

packages/dev-tools-pages/ts/variables.tsx

@@ -6,6 +6,7 @@ const colors = {
     lightGray: '#F1F4F5',
     gray: '#F1F2F7',
     darkGray: '#E9ECED',
+    darkestGray: '#E2E5E6',
     blueGray: '#ECEFF9',
 };