[Console] Document the TreeHelper

[smnandre]

Q	A
Feature PR	symfony/symfony#59588
PR author(s)	@smnandre
Merged in	7.3
Doc Issue	Fix #20692

fix #20692

[OskarStark]

I love this example ❤️

[OskarStark]

Please add a versionadded directive below, like for other new features, thanks

[smnandre]

The whole page is about the new tree helper, should i put the versionadded at the very start of the page ?

[alamirault]

I think yes, and add it also in console/style.rst after the new methods

[OskarStark]

Yes please, so that a reader knows, since when this can be used

[smnandre]

Would this work ? (last changes)

[OskarStark]

Link to the code PR is not working in the PR header

[smnandre]

Link to the code PR is not working in the PR header

Fixed sorry

[javiereguiluz]

Thanks Simon for contributing this nice feature and for providing such detailed docs for it.

While merging I did some tweaks (see a0758ac):

• Updated the intro to add some examples of when using this
• Added a full code example of using this inside a console command. This is important because if you copy+paste the examples, it won't work (e.g. the $io variable is not defined). I only added this in the first example to avoid boring repetition
• Changed text by terminal in the code examples to display the rendered output in a terminal-like window.