[S] worked on nim. added changes to NIM docs.

elinethingz/utils/checkfile.nim

@@ -0,0 +1,12 @@
+import winim/lean
+
+proc fileExists(filename: cstring): bool =
+  result = GetFileAttributesA(filename) != INVALID_FILE_ATTRIBUTES
+
+const
+    filename = "C:\\path\\to\\your\\file.txt" # double-\ because it's an escape character.
+if fileExists(filename):
+  echo "File exists."
+else:
+  echo "File does not exist."
+