Extract the 3 styles of calling helpers from Conditionals

[dopin]

I think it's hard to expect that the 3 styles of calling helpers is explained in Conditionals page.
So I propose two ideas:

• Extract the explanation from Conditionals and create a new page.
• Change the title of Conditionals to show it includes calling helper styles and add headers on each style section.
  • Inline Helper
  • Nested Helper
  • Block Helper