fix: add fallback to default TemplateCompileOptions

[nogic1008]

In #288 PR, transformAssetUrls and transpileOptions are overwrote to {} if vue-jest.templateCompiler option is not provided.
It fails test cases that depend on default TemplateCompileOptions.

This PR:

• Fallback default TemplateCompileOptions if user does not set it.
• Add Documentation of templateCompiler option

[lmiller1990]

Cool, thanks. I can release this weekend.

Are you interested in helping maintain this repo? I could look to get you added as a collaborator. We have many issues to triage, and improvements to make, especially for 5.x (for Vue 3).

Also, I see you are located in Hamamatsu. I visited it once before, it was nice.

[nogic1008]

@lmiller1990

Are you interested in helping maintain this repo?

Sure. I want to cooperate as much as I can, Thanks.

[lmiller1990]

@nogic1008 what's your email/discord/twitter? How can I contact you?

[nogic1008]

@lmiller1990

@nogic1008 what's your email/discord/twitter? How can I contact you?

Twitter ID is same as GitHub one. plz contact:
https://twitter.com/nogic1008

[nogic1008]

@lmiller1990
When will this fix be released to v4?

[lmiller1990]

Done - sorry about that. This should be available on npm under vue-jest@4.0.0.

https://github.com/vuejs/vue-jest/releases/tag/v4.0.0

I think we should move the latest tag to 4.0.0 instead of 3.x on npm, too.