Docugen-Microagents: simplify instructions and env setup

[alexsin368]

Implementing feedback from Dell.

README:

• Add supported model, API config, hardware matrix
• Added note on --enable-auto-tool-choice and --tool-call-parser as required model config arguments for Gaudi deployments since the Qwen model is deployed from HF which uses default arguments without these two, which are needed for the agents
• Simplify env setup

env setup:

• improve user experience with simplified instructions and variables set to work with Keycloak by default
• reduce to a single .env file

[psurabh]

LGTM