doc/go1.2.txt: text/template's if-else

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/13334043

doc/go1.2.txt

@@ -72,6 +72,7 @@ testing: AllocsPerRun is now quantized to an integer (the type is still float64)
 testing: add TB interface (intersection of T and B's methods) (CL 12962043).
 text/template: add comparison functions (CL 13091045).
 text/template: dereference pointer values when evaluating args escape funcs (CL 13257043).
+text/template: allow {{else if ... }} to simplify if chains (CL 13327043).
 time: Allow Parse and Format to handle time zone offsets with seconds (CL 8132044)
 time: patterns require non-lowercase letter to follow Mon, Jan etc (CL 12448044).
 unicode: add In, a nicer-to-use but equivalent version of IsOneOf (CL 11672044).