docs: improve auto routing

[kenjis]

Description

• improve description for Default Controller in Auto-Routing
• update for consistency

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• User guide updated
• [] Conforms to style guide

[michalsn]

This question is not very important, but why are we changing folder to directory everywhere? Do we stick to this convention on other pages? I have nothing against it, though.

[kenjis]

This is an explanation of subdirectories in Controllers, and there is no need to use the two terms folder and directory. Suddenly changing what we call a directory to a folder may confuse beginners.

I do not intend to change all folders in the user guide to directories.

[kenjis]

Can someone review?

[kenjis]

Thank you! @michalsn