Add helloworld example

examples/helloworld/helloworld.nim

@@ -0,0 +1,30 @@
+import libnx/gfx
+import libnx/console
+import libnx/hid
+import libnx/applet
+
+proc printf(formatstr: cstring) {.importc: "printf", varargs,
+                                  header: "<stdio.h>".}
+
+proc main() =
+  gfxInitDefault()
+
+  discard consoleInit(nil)
+
+  printf("\x1b[16;20HHello World From NIM!")
+  echo "\x1b[17;20HHELLO FROM NIM"
+  while appletMainLoop():
+    hidScanInput()
+
+    let keysDown = hidKeysDown(CONTROLLER_P1_AUTO)
+
+    if (keysDown and KEY_PLUS.uint64) > 0.uint64:
+      break
+
+    gfxFlushBuffers()
+    gfxSwapBuffers()
+    gfxWaitForVsync()
+
+  gfxExit()
+
+main()