add more cases to extarrange script....solving iiitl#7

scripts/extarrange

@@ -12,6 +12,10 @@ require egrep
 
 declare -A special_cases=(
     ['^*.(tar.*|tbz)$']='tar'
+    ['^*.(rar|rev|r00|r01)$']='rar'
+    ['^*.(doc.*|odt|pages|rtf|wpd|wps)$']='doc'
+    ['^*.(img|jpg|png)$']='img'
+    ['^*.(mp3|wav)$']='mp3'
     # TODO: Add your own pattern here for similar file types appropriately
     # Refer https://regex101.com/ & https://github.com/ziishaned/learn-regex/ for explaination and writing patterns
     # These (regex) are same as ones used in sed command