Add dev container for DELF project

[mirzaim]

The suggestion is for the DELF project.
https://github.com/tensorflow/models/tree/master/research/delf

I had some trouble making the DELF model work. It needs some dependencies and some of them had collisions with other projects.
I tried to use install_delf.sh script, but It also returns some errors. It takes some time and effort until I can use the project.

I think It is a good idea to build a dev container and dockerize the whole project. It's a lot easier for others to use it.

[chandrakanth-gudavalli]

I have built a docker image. Hope this will help to mitigate the issues with DELF installation.

• docker pull chandrakanthgudavalli/delf:v1.0.0
• docker run -it chandrakanthgudavalli/delf:v1.0.0 bash
• python3 -c "import delf" is working fine.

I am hoping this would help the other delf users.