raise error on multiple sibling variable paths collision

[tongueroo]

• Multiple Variables Path Issue Error Message Multiple Variables Path Issue Error Message  #143
• Add api gateway considerations docs

• This is a 🐞 bug fix.
• This is a 🙋‍♂️ feature or enhancement.
• This is a 🧐 documentation change.

• I've added tests (if it's a bug, feature or enhancement)
• I've adjusted the documentation (if it's a feature or enhancement)
• The test suite passes (run bundle exec rspec to verify this)

Summary

Raises error on multiple sibling variable paths collision.

Context

#143

Version Changes