Update all example URLs in the specifications to HTTPS

[dewitt]

As part one of updating the OpenSearch spec to be HTTPS-only (or at least, HTTPS-strongly-preferred), update all of the example URLs to be https instead of http.

[Krinkle]

It looks like the www.opensearch.org (redirect) supports HTTPS, but it has two issues currently:

1. It is a self-signed certificate.
2. It expired 3 years ago (in 2017).

Perhaps Let's Encrypt could be used here.

[dewitt]

That's a good catch, and we may be able to fix it, too. Though this issue was specifically about updating the specs to use HTTPS. I'll change the title of the issue to clarify. Thanks!

[RokeJulianLockhart]

http://github.com/dewitt/opensearch/issues/22#issue-553045623

http://datatracker.ietf.org/doc/html/rfc3986#section-4.2 may be preferrable, because none of this is necessarily information that is requiring security during observsation of it, and cryptography is able to be greatly detrimental to anyone whose internet-connection is slow.

However, this may only be applicable to embedded content. Thus, I am supportive of mere HTTP.

[baby933]

As part one of updating the OpenSearch spec to be HTTPS-only (or at least, HTTPS-strongly-preferred), update all of the example URLs to be https instead of http.