Host html without extension (.html)

### Check for existing issues

- [x] Completed

### Describe the feature

Upgrade the app like that the web pages host locally without extension (.html).

Eg.
If I click on 
`<a href="about">About</a>`
In http://localhost:3000/ then It should redirect to
http://localhost:3000/about.html



### If applicable, add mockups / screenshots to help present your vision of the feature


_No response_