README - install + command line run example

[amesar]

Install issues:

• "requests" is needed in requirements.txt
• for Mac M1 Pro the following is needed with brew: arch -arm64 brew install graphviz

Also be helpful have a snippet how to run the program from the command line such as:

python databricks.py \
   --db-workspace my-workspace \
   --db-token my-token \
   --model-name my-model \
   --model-version 12 \
  --output my-model.pdf