Feature Request: support plugins

[goodness-from-me]

I would like to be able to specify which plugins to load for adminer, similarly to how it is made with the official docker image.
Given I have provided the env variable like this:
ADMINER_PLUGINS='tables-filter tinymce'
I'd expect tables-filter and tinymce plugins to be added and loaded to my adminer container.

[f3l1x]

Hi, good idea, I need to implement it. No ETA at this moment, just for your info.