Rename constructor to game.New(game.Params) per styleguide

NewGame(Config) becomes New(Params), and Restore takes Params too, so
the package's primary type gets the canonical New() constructor with a
named-field Params struct (styleguide points 139, 159). cmd/rogue and
all tests updated; ARCHITECTURE.md constructor references corrected.
Pure rename, suite green.

game/effects_test.go

@@ -7,7 +7,7 @@ import "testing"
 func mkGameInput(t *testing.T) *RogueGame {
 	t.Helper()
 
-	g := NewGame(Config{Seed: 5, Term: &testTerm{}})
+	g := New(Params{Seed: 5, Term: &testTerm{}})
 	g.NewLevel()
 	g.Oldpos = g.Player.Pos
 	g.Oldrp = g.roomIn(g.Player.Pos)
@@ -183,7 +183,7 @@ func TestZapSlowMonster(t *testing.T) {
 }
 
 func TestParseOpts(t *testing.T) {
-	g := NewGame(Config{Seed: 1})
+	g := New(Params{Seed: 1})
 	g.ParseOpts("terse,nojump,name=Conan,fruit=mango,inven=slow")
 
 	if !g.Options.Terse {