Add tasks for all the new languages

Task/Dining-philosophers/Nim/dining-philosophers.nim

@@ -0,0 +1,41 @@
+import threadpool, locks, math, os
+randomize()
+
+type Philosopher = ref object
+  name: string
+  forkLeft, forkRight: int
+
+const
+  n = 5
+  names = ["Aristotle", "Kant", "Spinoza", "Marx", "Russell"]
+
+var
+  forks: array[n, TLock]
+  phils: array[n, Philosopher]
+  threads: array[n, TThread[Philosopher]]
+
+proc run(p: Philosopher) {.thread.} =
+  sleep random(1 .. 10) * 500
+  echo p.name, " is hungry."
+
+  acquire forks[min(p.forkLeft, p.forkRight)]
+  sleep random(1 .. 5) * 500
+  acquire forks[max(p.forkLeft, p.forkRight)]
+
+  echo p.name, " starts eating."
+  sleep random(1 .. 10) * 500
+
+  echo p.name, " finishes eating and leaves to think."
+
+  release forks[p.forkLeft]
+  release forks[p.forkRight]
+
+for i in 0 .. <n:
+  initLock forks[i]
+  phils[i] = Philosopher(
+    name: names[i],
+    forkLeft: i,
+    forkRight: (i+1) mod n)
+  threads[i].createThread run, phils[i]
+
+threads.joinThreads