Add latex pack

### Is your feature related to a problem?

Lack of niceties when working with latex

### Describe the new feature

https://github.com/latex-lsp/texlab

https://github.com/ltex-plus/ltex-ls-plus

https://www.reddit.com/r/neovim/s/IMynDbihZo

### Additional context

Why is texlab not offered by many vimtex users seems odd

The inline math display is nice though

Anyway i just felt sharing my finding here, do with it what you like

Start by reviewing the linked texlab and ltex-ls-plus projects and the Reddit discussion to determine the requested LaTeX integration. Then inspect the repository's existing plugin-pack conventions; done requires an agreed feature scope and a corresponding pack added, but this issue names no files or tests.

Written by the indexing model from the issue text.