Docs: articles/https minor amendments and update

This commit proposes some minor amendments and updates
for the articles/https.md document to fix certain errors, inc.:

 - Marking commands / flags as code (e.g. `tlsverify`) [done before rebase]
 - Capitalising the word Docker
 - Normalizing headers to match the rest of the docs;
 - Expanding the page description to match the page title and the content;
 - Capitalizing HTTPS etc.;
 - Some spelling error fixes;
 - Line-length adjustments to make it easier to read the raw file.

It does not propose any fundemental changes to the structure of the document.
Certain changes were based before another update on this doc.

Docker-DCO-1.1-Signed-off-by: O.S. Tezer <ostezer@gmail.com> (github: ostezer)
Merge pull request #7327 from ostezer/fix-articles-https

Docs: articles/https minor amendments and update