Add core regions to .info file

valencia.info

 name = Valencia
 description = A theme developed by the Ubuntu Italy community.
 core = 7.x
-version = 0.1
\ No newline at end of file
+version = 0.1
+
+; CORE REGIONS - REQUIRED
+regions[page_top] = Page Top
+regions[content] = Content
+regions[page_bottom] = Page Bottom
+
+; CORE REGIONS - ENABLED
+regions[header] = Header
+regions[footer] = Footer
+
+; CORE REGIONS - DISABLED
+;regions[highlighted] = Highlighted
+;regions[help] = Help
+;regions[sidebar_first] = Sidebar First
+;regions[sidebar_second] = Sidebar Second
\ No newline at end of file