[Fixes] Set-ModuleReadMe when called w/ relative path

[MrRoundRobin]

Description

When Set-ModuleReadMe was called inside the same directory as the bicep file, there was an error and the readme could not be created.

This PR will fix this by resolving relative paths to full paths.

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update (Wiki)

Checklist

• I'm sure there are no other open Pull Requests for the same update/change
• My corresponding pipelines / checks run clean and green without any errors or warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (readme)
• I did format my code