Support using <details> tag if the text is long

[suzuki-shunsuke]

Overview

Support using <details> tag if the text is long.

For example, when over 10 resources are changed, updated resources are wrapped with <details>.

Why is this feature needed?

It makes the comment slim.
Too long text is a bit noisy.

How

• Add a template function that wraps a text if the text is long
• Update the default template using the function

Reference

• https://suzuki-shunsuke.github.io/tfcmt/config#template-functions
• https://pkg.go.dev/text/template