Merge pull request #1075 from flaviut/inlinedocs

Add some documentations and code examples in system

tests/misc/tnoinst.nim

@@ -0,0 +1,16 @@
+discard """
+  line: 12
+  errormsg: "instantiate 'notConcrete' explicitly"
+"""
+
+proc wrap[T]() =
+  proc notConcrete[T](x, y: int): int =
+    var dummy: T
+    result = x - y
+
+  var x: proc (x, y: T): int
+  x = notConcrete
+  
+
+wrap[int]()
+