Allow local directories to be passed to --template as relative paths.

[ryanwelcher]

Description

Check to see if the item passed to the --template flag is a directory and if so, resolve it to allow it to be loaded.

When checking to see how the current tool handles local templates, I found that I was able to pass an absolute path to a template and it worked fine. This PR takes the approach of checking if the passed value is an actual directory and if so, resolving it to an absolute path. Otherwise, it operates as normal.

How has this been tested?

This was testing running the package locally via node.

Screenshots

Types of changes

New feature.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[ryanwelcher]

Closes #34547

[mkaz]

This worked well in my testing, and code looks good.

I tested by checking out my richtext-block template.

1. Updated and built gutenberg based off this PR.
2. git clone https://github.com/mkaz/mkaz-block-template
3. Ran script specifying template
   ../node_modules/.bin/wp-create-block --template ./mkaz-block-template

Confirmed the new block created was based off my template.

Good work, thanks for implementing 👍