Allows us to set environment variables that could be the named the same between multiple steps, but have different values due to enivronmental differences.
This is a redo of #28 because I'm bad at git. The secrets are exported so that they can be used in any other flag in this plugin.
* Adding targets section for configuration
Will add a --target <resource> for each item in a comma separated list to the plan and apply commands
Updated the docs to show the new behavior. If left undefined there is no regression in functionality.
* Combine the --target append steps
No reason to waste lines
* Updating docs for YAML list of strings
* Documentation for single and multiple targets
