Add search form when uri not provided

[evankanderson]

This came up during the OpenSSF Scorecards & Best Practices meeting -- the "install nothing" scorecards are great, but it would be even better to make them easier to find...

[netlify]

👷 Deploy request for ossf-scorecard pending review.

Visit the deploys page to approve it

Name	Link
🔨 Latest commit	77502d0

[evankanderson]

A follow-on would be to link to this viewer from the ossf/scorecards repo with something like the following image and an invitation to check out your own project:

[evankanderson]

@spencerschrock -- can you review?

[spencerschrock]

I've enabled the development preview at:
https://deploy-preview-467--ossf-scorecard.netlify.app/viewer/

Can take another look later.

[spencerschrock]

Thanks. You'll need to DCO all commits before I can get this in:

Commit sha: b9f0bd3, Author: Evan Anderson, Committer: Evan Anderson; The sign-off is missing.

Instructions on fixing it can be found with the bot:

https://github.com/ossf/scorecard-webapp/pull/467/checks?check_run_id=16963946201

[evankanderson]

Fixed the DCO as well, and re-merged the upstream changes.

[spencerschrock]

Thanks!