Add TODO.nits file intended to document small

/*XXX this is straightforward to fix but I have no time right now */
tasks so we don't lose track of them.

Format and purpose are documented at the top of the file.

Discussed with Christos and others

doc/TODO.nits

@@ -0,0 +1,25 @@
+#	$NetBSD: TODO.nits,v 1.1 2005/09/10 18:30:30 perry Exp $
+#
+# This file documents small nits in our code (often marked in comments
+# with /* XXX */) and similar "small fixes needed" so that they will not
+# be forgotten.
+# 
+# Generally speaking, this file represents a queue of small,
+# straightforward things to fix. If something is a serious project, it
+# should probably go in to TODO. If it is unlikely something will ever
+# be fixed, do not put it in this file, just document it in a comment.
+# 
+# The entry format is:
+# 
+#   YYYY-MM-DD (userid) Explanation
+# 
+# The date is the date the nit was first added.
+#
+# Try to keep the format consistent -- we may want to machine parse it
+# someday.
+# 
+# Add new nits at the bottom of the file. Remove old nits as you fix
+# them.
+
+2005-09-10 (christos) Convert src/lib/libc/rpc to use kqueues, the way
+    FreeBSDs does.