Administration: Correct the URL for "Learn more about getting started" link in...

Administration: Correct the URL for "Learn more about getting started" link in "Welcome to WordPress" panel.

Props hareesh-pillai, johnbillion.
Fixes #50484.
Built from https://develop.svn.wordpress.org/trunk@48191


git-svn-id: https://core.svn.wordpress.org/trunk@47960 1a063a9b-81f0-0310-95a4-ce76da25c4cd