Upgrade uncharted_phoenix to use heex format

[abhinavs]

Hi,

I'm trying to use uncharted_phoenix with the latest version of Phoenix and LiveView. I modified most of the files, and the code seems to be compiling, but installing it as a dependency inside a Phoenix project gives a compilation error.

I'm new to Phoenix LiveView and Elixir, and have primarily written application code. This is my first time updating a library code, and I'm stuck.

Here is the updated code in my forked version - https://github.com/abhinavs/uncharted/tree/master/uncharted_phoenix