Update links in docs

[Gonchik Tsymzhitov]

Hi team, 

Today one of my team member do upgrade of Bamboo, 

during some troubleshooting the docs show the link to answer.atlassian.com.

https://confluence.atlassian.com/bamboo/bamboo-upgrade-guide-720411366.html

Is it possible to point to community.atlassian.com and super helpful will be if link point to Bamboo products

https://community.atlassian.com/t5/Bamboo/ct-p/bamboo

or as additional option type you can choose a product. 

And will be helpful to adjust the link to the KB.

Thank you for your help.

Cheers,

Gonchik Tsymzhitov