Add a useful sitewide search to backdropcms.org

[jenlampton]

It's been brought up in chat several times that people would expect to find a search box on backdropcms.org. We don't currently have one.

Here are some of the reasons we don't have a search box today: 1) We are worried that what people really want when they run a search on backdropmcs.org is probably not going to be available on backdropcms.org. (likely on the docs site, forum, or events site) 2) back in the early days of backdropcms.org, search was used for the results of the modules/themes/layouts pages (and nothing else) so the search results were heavily themed for that purpose (only)

Next steps for adding a site-wide search include:

• Test: enable the search module on a local, or beta site - visit /search, run a search, and see how terrible the search results look in the borg theme.
• Design: decide where to put a search box on b.org (and all other b.org sites)

Update the borg theme based on the above:

• Support a search box in the approved location
• Search results look nice (regardless of node type)

Other necessary changes

• Add a text block on the search results page recommending a similar search on docs.backdropcms.org. This should include a link to docs.backdropcms.org with the exact same query string, and should be under a heading like "Not finding what you are looking for?"
• If determined by testing, undo any previous custom search work that was done for legacy project listing pages

Nice-to-haves

• Design: (not a blocker, but should be high on the priority list) come up with a useful layout for a search results page, that doesn't put all node types into the same list.
  • We'll need to put some thought into what people are most likely searching for, and keep those things into the main results area. Other things that are less likely (but still wanted) could be moved into sidebars, etc.
• We should also consider adding advanced search or facet filters to the search results page, to help people find what they are looking for faster. (this may require user testing)
• We may also choose to add search API module to make a separate index of nodes + users together, for a search experience that's closer to expectations

[stpaultim]

This looks like something we can at least make progress on during Infrastructure week. I'm adding it to the project.

[irinaz]

Related to https://github.com/backdrop-ops/backdropcms.org/issues/370