In demo, fix text in tooltip of “typographer” option (#600)

- Fix spelling of “typographic”
- Use the proper arrow symbol (which is important because using the correct symbols is the point of this option)

support/demo_template/index.pug

@@ -65,7 +65,7 @@ html
             input#linkify(type='checkbox')
             |  linkify
         .checkbox.not-strict
-          label._tip(title='do typographyc replacements, (c) -> © and so on')
+          label._tip(title='do typographic replacements, (c) → © and so on')
             input#typographer(type='checkbox')
             |  typographer
         .checkbox.not-strict