unitframes: add combat hit indicators

thanks @Jayrgo for his work on that.

env/translations_enUS.lua

@@ -171,6 +171,7 @@ pfUI_translation["enUS"] = {
   ["Enable Energy Ticks"] = nil,
   ["Enable Extended Guild Information"] = nil,
   ["Enable Health Color"] = nil,
+  ["Enable Hit Indicator"] = nil,
   ["Enable Item Quality Color For Equipment Only"] = nil,
   ["Enable Left Actionbar (BottomRight)"] = nil,
   ["Enable Level Color"] = nil,
@@ -247,6 +248,9 @@ pfUI_translation["enUS"] = {
   ["Hide Group Frames While In Raid"] = nil,
   ["Hide Totems"] = nil,
   ["Highlight Settings That Require Reload"] = nil,
+  ["Hit Indicator"] = nil,
+  ["Hit Indicator Text Font"] = nil,
+  ["Hit Indicator Text Size"] = nil,
   ["Hoverbind"] = nil,
   ["Huge (PixelPerfect)"] = nil,
   ["Icon Size"] = nil,