Make script more user friendly

[tuetenk0pp]

As pointed out here:

Hi Tuetenk0pp,
I used your script and in the end it worked. I only stumbled over the fact that the webtrees-startup-assistant asked the same questions as your script and I put in different values. It is important that you use the same names, e.g. the default values as in the script:

Base URL: localhost
Database Name: webtrees
Database User: webtrees
Database Password: ***

Perhaps you could add this information in your readme file for noobs like me.
Thank you for the script. It is the only help I found in the web to run webtrees without studying computer science before.
Best regards
Martin