[Documentation Update]: Enhance Bicep Contribution Flow Step 4 (reduce assumptions of knowledge)

### Check for previous/existing GitHub issues

- [x] I have checked for previous/existing GitHub issues

### Description

In [Step 4 of the Bicep Contribution Flow](https://azure.github.io/Azure-Verified-Modules/contributing/bicep/bicep-contribution-flow/#4-implement-your-contribution) there is a lot of assumption that the consumer is aware exactly what to do.

This section should be updated to include more basic/clear step by step high level steps like:

1. Add new your modules GitHub actions workflow file to your forks main branch
2. then create a branch
3. then create the module directory
4. then run `set-AVM module …`
5. etc.

Just to help contributors feel less overwhelmed and confused 👍

Cc: @matebarabas