Use CSS in rule descriptions

[lmarniazman]

This is a follow up for issue #68 fixed by PR #69

As commented in the PR, we should define the used color codes in a central place, as all rule descriptions make use of the same coloring. This would reduce redundancy and make future refactorings a lot easier.

Since using CSS in rule descriptions doesn't seem to be that straightforward, we might need to find a workaround, maybe as suggested by @hohwille:

As a nice-to-have we can later ask in SonarQube forum for help how CSS could be used or try some own solution e.g. via generation by processing the HTML with maven during the build...

EDIT: Topic on the SonarSource forum

[lmarniazman]

There was an answer from the SonarQube team for this issue:
They support basic HTML without style information in their rule description. There is currently no plan to add styling.
For the full answer, see the topic referenced in the original issue text.