[CentOS-docs] Comments on draft TipsAndTricks/InstallWebminRepo page

Dear Vladislav Rastrusny,

> Applied your fixes, thanks a lot!

Is there any good reason for CamelCasing WebMin (sometimes)? The
official spelling seems to be Webmin.

Also I wonder why you don't just offer a signed RPM package with the
repo description or alternatively just a repo file for download. Maybe
you could get in contact with Jamie Cameron to do so.

Best Regards
Marcus