I suggest improving install steps for CentOS 8

Hello,

I have found a problem with the following page.

page: https://www.postgresql.org/download/linux/redhat/

I tried install PostgreSQL12 into CentOS 8 as written on this page.
However, I couldn't install it by the following error.

# dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm
# dnf install -y postgresql12
Failed to set locale, defaulting to C
PostgreSQL 10 for RHEL/CentOS 8 - x8 100 kB/s | 539 kB 00:05
PostgreSQL 11 for RHEL/CentOS 8 - x8 121 kB/s | 629 kB 00:05
PostgreSQL 12 for RHEL/CentOS 8 - x8 91 kB/s | 471 kB 00:05
PostgreSQL 9.4 for RHEL/CentOS 8 - x 75 kB/s | 361 kB 00:04
PostgreSQL 9.5 for RHEL/CentOS 8 - x 108 kB/s | 425 kB 00:03
PostgreSQL 9.6 for RHEL/CentOS 8 - x 55 kB/s | 518 kB 00:09
No match for argument: postgresql12
Error: Unable to find a match

There is a workaround for this problem.
I executed a below command.
I could install it.

# dnf module disable postgresql

This problem has already reported to Red Hat Bugzilla.
(https://bugzilla.redhat.com/show_bug.cgi?id=1718201#c1)

However, this problem has been already closed.
Because it seems that is not a bug.

Therefore I suggest that add a workaround in this document like an
attachment.

Thanks,