Prefer https over http in docs and commentary

[rolandwalker]

Description

Prefer http over https in docs and commentary, also updating the "click" link to a new domain which supports HTTPS.

Checklist

• I added this contribution to the changelog.md file.
• I added my name to the AUTHORS file (or it's already there).
• To lint and format the code, I ran

  uv run ruff check && uv run ruff format && uv run mypy --install-types .

[github-actions]

Findings (correctness/regression)

1. Doc intent mismatch: PR title/body says “Prefer http over https,” but the actual changes flip links to https and the changelog says “Prefer https protocol over http.” This is confusing and could lead to the wrong direction being merged. Please align title/body/changelog with the actual intended behavior. Affected: README.md, changelog.md.
2. Potential link regressions: mycli.net and pgcli.com are switched to https without evidence in the PR. If those domains don’t support TLS or have mixed-content quirks, users could see broken links. Please confirm they support https (and ideally redirect from http) before merging. Affected: README.md, mycli/main.py, mycli/myclirc, test/myclirc.

Security

• No direct security issues found.

Tests / edge cases

• No tests needed for doc-only changes, but if the intent is to require https, a quick manual verification of the endpoints would prevent regressions.

Open questions

• Which is the correct policy: prefer http or https? The PR currently implements https.