Add Lesser Elemental Rune Quest Reward

As a quest reward during the campaign playthrough, I would like to propose to GGG to add a source of elemental resistance runes, which are essential for surviving the campaign. This quest reward could be from a main quest or side quest in any particular act.

* Quest Reward: choice of one of the three Lesser Elemental Runes: Desert (Fire), Glacial (Cold), or Storm (Lightning).