Add "questions.txt", a place where spec-related implementation

questions can be asked/answered.

questions.txt

@@ -0,0 +1,33 @@
+This file contains miscellaneous questions about design and
+specification that implementors have come up with that are
+awaiting answers from Larry (TimToady) and/or others.
+Answers are recorded here as well, but are moved into a
+lower section of the file to keep the as-yet unanswered 
+questions on top.  It's like an absurdly simple ticket system.
+
+(See https://github.com/perl6/mu/blob/master/misc/pm.txt for
+a previous incarnation of this file.)
+
+As yet unanswered questions:
+
+Q1: (pmichaud) Does numifying or stringifying a type object
+    produce an immediate 'warn' or a Failure?  What's the
+    expected result from:
+
+        my $x;
+        my $y = +$x;
+        say 'alive';
+        say $y;
+
+    Is the warning generated at the point of assignment to $y
+    or at the point where $y is used?
+
+
+Q2: (pmichaud) What's the expectation of how "useless use of '+'
+    in sink context" messages will be generated?  Are they
+    generated at compile-time based on a trait of the (proto) sub,
+    or is it something that &infix:<+> would detect and carp
+    about at runtime?
+
+
+Pm