feat(template): support pug template

[yanskun]

Types of changes

• [x] New feature (a non-breaking change which adds functionality)

Description

create-nuxt-app is essential for creating Nuxt Project and I love it. That's why I use this over and over again.

I prefer Pug over HTML because it's easier to read. Also, I feel that there are many such friends. (#378)

After creating-nuxt-app, every time pug is installed and the page file is changed to <template lang="pug">.

I wanted to solve this, so I tried to fix it this time! thank you

Checklist:

• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes (if not applicable, please state why)

[yanskun]

@Atinux (I didn't know who to mention) I love Nuxt, and love Pug just as much.

I feel this is not actively developed. However, until Nuxt3 is officially released, it will be used.

How can I get you to review.

[Atinux]

Thank you for your help @yanskun

I added Clark as review since he has been working a lot on this project.