Add tasks for all the new languages

Task/Find-common-directory-path/Nim/find-common-directory-path.nim

@@ -0,0 +1,13 @@
+import strutils
+
+proc commonprefix(paths: openarray[string], sep = "/"): string =
+  if paths.len == 0: return ""
+  block outer:
+    for i in 0..paths[0].len:
+      result = paths[0][0..i]
+      for path in paths:
+        if not path.startsWith(result):
+          break outer
+  result = result[0 .. <result.rfind(sep)]
+
+echo commonprefix(@["/home/user1/tmp/coverage/test", "/home/user1/tmp/covert/operator", "/home/user1/tmp/coven/members"])