Update numbers.md

doc/proposals/numbers.md

@@ -8,12 +8,14 @@ The last time we looked at this, we concluded we didn't have a clear enough idea
 
 It's now clear to me that desiderata include:
 
-Use cases:
+## Use cases
+
 * It should be possible to store arbitrarily large integers in Noms
 * It should be possible to store arbitrarily precise non-integral numbers in Noms
 * It should be possible to store rational, non-integral numbers precisely in Noms
 
-Integration:
+## Integration
+
 * The Noms type system should report useful information about numbers:
   * Whether the number can be represented precisely in binary
   * The number of bits required to represent a number precisely
@@ -23,12 +25,15 @@ Integration:
 * It should be possible to use native Go numeric types like `int64`, `float`, and `big.Rat` to work with Noms numbers in the cases they fit
 * It should be possible to conveniently work with _all_ Noms values via some consistent interface if so desired
 
-Efficiency:
+## Efficiency
+
 * It should be as close as possible to zero work to decode and encode all the common numeric types
 * Large, imprecise numbers (e.g., 2^1000) should be stored compactly so that users don't have to manually mess with scale to try and save space
 
-Non-goals:
+## Non-goals
+
 * I do not think a database system like Noms should support fixed-size (e.g., floating point) fractional values.
+* I do not care if it is possible to represent every possible IEEE float (e.g., NaN, Infinity, etc)
 
 # Proposal for type system integration