More operators and docs update

Signed-off-by: Heinz N. Gies <heinz@licenser.net>

static/language/epilog/for.md

@@ -38,9 +38,6 @@ For creating the product of numbers in a array we use:
   end
 ```
 
-The current supported operators in `use` are: `+`, `-`, `*` and `/`.
-
-
-
-The `ForCaseClause` rule has examples of the two basic forms for record and array comprehensions.
+For a overview of supported operators see the [operators](./../expressions/#operators) section.
 
+The `ForCaseClause` rule has examples of the two basic forms for record and array comprehensions.

tests/script_errors/bad_fold/error.txt

@@ -2,4 +2,4 @@ Error:
     1 | for event of
     2 |   case (k, v) => v
     3 | into [] use merge end;
-      |             ^^^^^ Found the token `merge` but expected one of `*`, `+`, `-`, `/`
+      |             ^^^^^ Found the token `merge` but expected one of `%`, `&`, `*`, `+`, `-`, `/`, `^`

tests/script_errors/bad_fold_imut/error.txt

@@ -2,4 +2,4 @@ Error:
     1 | (for event of
     2 |   case (k, v) => v
     3 | into [] use merge end)
-      |             ^^^^^ Found the token `merge` but expected one of `*`, `+`, `-`, `/`
+      |             ^^^^^ Found the token `merge` but expected one of `%`, `&`, `*`, `+`, `-`, `/`, `^`

tremor-script/src/grammar.lalrpop

@@ -1272,10 +1272,10 @@ MaybeFoldOperator: Option<ComprehensionFoldOpRaw> = {
 }
 
 FoldOperator: ComprehensionFoldOpRaw = {
-    "+" => ComprehensionFoldOpRaw(BinOpKind::Add),
-    "-" => ComprehensionFoldOpRaw(BinOpKind::Sub),
-    "*" => ComprehensionFoldOpRaw(BinOpKind::Mul),
-    "/" => ComprehensionFoldOpRaw(BinOpKind::Div),
+    <BinAdd> => ComprehensionFoldOpRaw(<>),
+    <BinMul> => ComprehensionFoldOpRaw(<>),
+    <BinBitAnd> => ComprehensionFoldOpRaw(<>),
+    <BinBitXor> => ComprehensionFoldOpRaw(<>),
 }
 
 ForCaseClauses: ComprehensionCasesRaw<'input, ExprRaw<'input>> = {