fix: When the dataDir is configured in taos.cfg, the env DATA_DIR is wrong.

* [TD-12903]<feat>(other): support environment variables in docker image

* [TD-12903]<feat>(other): expose ports used by taosadapter and udp ports in docker

* [TD-12903]<feat>: run taosd directly when TAOS_FIRST_EP not set

* [TD-13060]<docs>: add docker image user manual

* chore: update docker image readme