Remove search on UserHelp

[maxime-rainville]

Following https://github.com/silverstripe/doc.silverstripe.org/issues/263, we've decided to remove search from UserHelp.

Acceptance criteria

• Search is off on UserHelp
• Search is on on Developer doc

Note

• We will potentiall move the doc to a new place in the process of rebuilding silverstripe.org. Keep that in mind while fixing the doc.

[GuySartorelli]

This isn't happening anymore, since algolia ended up setting us up an application for it.