Document use of () for installing methods for ops w/ low precedence

Author: d-torrance

M2/Macaulay2/m2/help.m2

@@ -303,6 +303,8 @@ getOperator := key -> if operator#?key then (
 		"The user may install ", TO "Macaulay2Doc :: binary methods", " for handling such expressions with code such as"},
 	    PRE if key === symbol SPACE
 	    then "         X Y := (x,y) -> ..."
+	    else if (getParsing key)#0 <= (getParsing symbol :=)#0
+	    then "        (X "|op|" Y) := (x,y) -> ..."
 	    else "         X "|op|" Y := (x,y) -> ...",
 	    PARA {"where ", TT "X", " is the class of ", TT "x", " and ", TT "Y", " is the class of ", TT "y", "."}},
 	if key === symbol ?? then { -- can't install binary methods

M2/Macaulay2/packages/Macaulay2Doc/operators/assignment.m2

@@ -45,7 +45,10 @@ document {
 	       },
 	  EXAMPLE lines ///
 	       installMethod(symbol <-, String, peek)
-	  ///
+	  ///,
+	  PARA { "The following syntax may also be used.  Note that the parentheses on the left hand side are necessary because of the low precedence of the ",
+	      CODE "<-", " operator."},
+	  EXAMPLE "(<- String) := peek"
 	  ),
      SYNOPSIS (
 	  Heading => "using installed assignment methods",

M2/Macaulay2/packages/Macaulay2Doc/operators/shift.m2

@@ -19,6 +19,8 @@ document {
      Key => symbol >>,
      Headline => "a binary operator, used for bit shifting or attaching optional inputs to functions",
      SeeAlso => { (symbol >>, OptionTable, Function) },
+     Caveat => {"Due to its low precedence, parentheses must be used on the left hand side when installing methods for this operator, e.g., ",
+	 CODE "(X >> Y) := f", "."},
      Subnodes => { TO "right shift" }
      }