Investigate replacing nvim-lspconfig dependency with `vim.lsp.start`

[jose-elias-alvarez]

I originally wanted this plugin to be independent but quickly found that replacing nvim-lspconfig meant reinventing the wheel (which was particularly painful when going through TypeScript). vim.lsp.start makes this a lot easier, though I still think there's a good amount of effort required to reach parity with nvim-lspconfig.

I've been able to set up a minimal example pretty easily, but I think it's the edge cases that make this difficult. I want to investigate how feasible this is and check out other plugins using vim.lsp.start to see how they're handling it, because I do think removing the dependency is the right path forwards.