Updates reflecting FS1091 (UoM for more typs) (#37)

Updated the chapter on units of measure, and the introduction, to
reflect the changes introduced by
[FS-1091](https://github.com/fsharp/fslang-design/blob/main/FSharp-6.0/FS-1091-Extend-Units-of-Measure.md).

---------

Co-authored-by: Edgar Gonzalez <edgargonzalez.info@gmail.com>

Author: pblasucci

spec/front-matter.md

@@ -10,6 +10,7 @@ and does not yet incorporate all RFCs since F# 4.1 (including some of the 4.1 RF
 | --- | --- |
 | FS-1005 | underscores in numerical fields |
 | FS-1006 | struct tuples |
+| FS-1091 | units of measure for more types |
 
 ## Notices
 

spec/introduction.md

@@ -264,9 +264,9 @@ let htmlOfSites =
 
 By using asynchronous workflows together with other CLI libraries, F# programs can implement parallel tasks, parallel I/O operations, and message-receiving agents.
 
-### Strong Typing for Floating-Point Code
+### Strong Typing for Numerical Code
 
-F# applies type checking and type inference to floating-point-intensive domains through *units of measure inference and checking*. This feature allows you to type-check programs that manipulate floating-point numbers that represent physical and abstract quantities in a stronger way than other typed languages, without losing any performance in your compiled code. You can think of this feature as providing a type system for floating-point code.
+F# applies type checking and type inference to numerically-intensive domains through *units of measure inference and checking*. This feature allows you to type-check programs that manipulate numerical values that represent physical and abstract quantities in a stronger way than other typed languages, without losing any performance in your compiled code. You can think of this feature as providing a type system for numerical code.
 
 Consider the following example: