Added two text editors so users can choose which one to use

[gansbrest]

The Docker container used in the the instructions https://github.com/AntonOsika/gpt-engineer/blob/main/docker/README.md does not have text editors and breaking gpte in the -i (improve) mode.

This fixes https://github.com/AntonOsika/gpt-engineer/issues/1200 and provides a choice between two text editors vim and nano that can be made with -e EDITOR env variable during docker run. Nano will be used by default.

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[!IMPORTANT] Adds vim and nano to Docker container, allowing editor choice via -e EDITOR env variable, defaulting to nano.

• Dockerfile Changes:
  • Adds vim and nano to the Docker container in docker/Dockerfile.
• Behavior:
  • Fixes issue with -i mode in gpte by providing text editors.
  • Allows editor choice via -e EDITOR environment variable during Docker run, defaulting to nano.

^{This description was created by for 5831bb3d88d37f85d7d87ad23d7355da790f38bd. It will automatically update as commits are pushed.}