Adjusted URLs

Adjusted URLs

Most of these sites support HTTPS (some forward to HTTPS when accessing
the HTTP versions). Use HTTPS directly if supported.

Some URLs led to 404 error pages. Adjusted the links to point to
new locations.

I did not adjust the Microsoft HTML Help Workshop link because it seems
that this software is not available anymore. Instead of removing the
link entirely I kept it there in case it helps someone to find the
software on archived websites.