Docs: fix typos of 'whether' in operator_{gt,le,lt}.md (nlohmann#4412)

Author: tsnl

docs/mkdocs/docs/api/basic_json/operator_gt.md

@@ -17,7 +17,7 @@ bool operator>(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
       operand is `NaN` and the other operand is either `NaN` or any other number.
     - Otherwise, returns the result of `#!cpp !(lhs <= rhs)` (see [**operator<=**](operator_le.md)).
 
-2. Compares wether a JSON value is greater than a scalar or a scalar is greater than a JSON value by
+2. Compares whether a JSON value is greater than a scalar or a scalar is greater than a JSON value by
    converting the scalar to a JSON value and comparing both JSON values according to 1.
 
 ## Template parameters

docs/mkdocs/docs/api/basic_json/operator_le.md

@@ -17,7 +17,7 @@ bool operator<=(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
       operand is `NaN` and the other operand is either `NaN` or any other number.
     - Otherwise, returns the result of `#!cpp !(rhs < lhs)` (see [**operator<**](operator_lt.md)).
 
-1. Compares wether a JSON value is less than or equal to a scalar or a scalar is less than or equal
+1. Compares whether a JSON value is less than or equal to a scalar or a scalar is less than or equal
    to a JSON value by converting the scalar to a JSON value and comparing both JSON values according
    to 1.
 

docs/mkdocs/docs/api/basic_json/operator_lt.md

@@ -27,7 +27,7 @@ bool operator<(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
         7. binary
       For instance, any boolean value is considered less than any string.
 
-2. Compares wether a JSON value is less than a scalar or a scalar is less than a JSON value by converting
+2. Compares whether a JSON value is less than a scalar or a scalar is less than a JSON value by converting
    the scalar to a JSON value and comparing both JSON values according to 1.
 
 ## Template parameters