Add tasks for all the new languages

Task/Semordnilap/Nim/semordnilap.nim

@@ -0,0 +1,16 @@
+import strutils, sequtils, sets, algorithm
+
+proc reverse(s): string =
+  result = newString(s.len)
+  for i,c in s:
+    result[s.high - i] = c
+
+let
+  words = readFile("unixdict.txt").strip.splitLines
+  wordset = words.toSet
+  revs = words.map(reverse)
+var pairs = zip(words, revs).filterIt(it[0] < it[1] and it[1] in wordset)
+
+echo "Total number of semordnilaps: ", pairs.len
+pairs.sort(proc (x,y): auto = cmp(x[0].len,y[0].len))
+echo pairs[pairs.high-4..pairs.high]