Updated Scala files extensions

Added syntax highlighting for Scala files with .sc and .sbt extensions

scala.nanorc

@@ -1,6 +1,6 @@
 ## Here is an example for Scala.
 ##
-syntax "Scala" "\.scala$"
+syntax "Scala" "\.(scala|sc|sbt)$"
 color green "\<(boolean|byte|char|double|float|int|long|new|short|this|transient|void)\>"
 color red "\<(match|val|var|break|case|catch|continue|default|do|else|finally|for|if|return|switch|throw|try|while)\>"
 color cyan "\<(def|object|case|trait|lazy|implicit|abstract|class|extends|final|implements|import|instanceof|interface|native|package|private|protected|public|static|strictfp|super|synchronized|throws|volatile|sealed)\>"