1982: Change memory requirements r=mergify[bot] a=teadur
Running with ClamAV requires atleast 3GB of memory otherwise ClamAV updates fail and fill the disk https://github.com/Mailu/Mailu/issues/470
## What type of PR?
documentation
## What does this PR do?
### Related issue(s)
- Information from #470
## Prerequisites
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.
Co-authored-by: Georg <teadur@users.noreply.github.com>
Co-authored-by: Dimitri Huisman <diman@huisman.xyz>