Soften language about operator suffix spacing

Author: moble

doc/src/manual/variables.md

@@ -114,9 +114,9 @@ to the addition function, and `(+) = f` will reassign it. Most of the Unicode in
 category Sm), such as `⊕`, are parsed as infix operators and are available for user-defined methods
 (e.g. you can use `const ⊗ = kron` to define `⊗` as an infix Kronecker product). Operators can also be
 suffixed with modifying marks, primes, and sub/superscripts, e.g. `+̂ₐ″` is parsed as an infix operator
-with the same precedence as `+`. A space is required between an operator that ends with a
+with the same precedence as `+`. A space should be used between an operator that ends with a
 subscript/superscript letter and a subsequent variable name. For example, if `+ᵃ` is an operator, then
-`+ᵃx` must be written as `+ᵃ x` to distinguish it from `+ ᵃx` where `ᵃx` is the variable name.
+`+ᵃx` should be written as `+ᵃ x` to distinguish it from `+ ᵃx` where `ᵃx` is the variable name.
 
 A particular class of variable names is one that contains only underscores. These identifiers are write-only. I.e. they can only be assigned values, which are immediately discarded, and their values cannot be used in any way.