feat(lang): add tex support (#1156)

* feat(lang): add tex support

* Reword comments

* Remove personalise configs.

* Disable lazy-loading.

* Remove chktex in LSP server texlab.

* Update local conceallevel setup.

* Add keymap for vimtex-doc-package.

* Enable vimtex omni-completion.

* Update vimtex's keymap.

* refactor: move vimtex K to texlab

---------

Co-authored-by: Folke Lemaitre <folke.lemaitre@gmail.com>

lua/lazyvim/plugins/extras/lang/tex.lua

@@ -0,0 +1,58 @@
+return {
+  {
+    "folke/which-key.nvim",
+    optional = true,
+    opts = {
+      defaults = {
+        ["<localLeader>l"] = { name = "+vimtex" },
+      },
+    },
+  },
+
+  -- Add BibTeX/LaTeX to treesitter
+  {
+    "nvim-treesitter/nvim-treesitter",
+    opts = function(_, opts)
+      if type(opts.ensure_installed) == "table" then
+        vim.list_extend(opts.ensure_installed, { "bibtex", "latex" })
+      end
+      if type(opts.highlight.disable) == "table" then
+        vim.list_extend(opts.highlight.disable, { "latex" })
+      else
+        opts.highlight.disable = { "latex" }
+      end
+    end,
+  },
+
+  {
+    "lervag/vimtex",
+    lazy = false, -- lazy-loading will disable inverse search
+    config = function()
+      vim.api.nvim_create_autocmd({ "FileType" }, {
+        group = vim.api.nvim_create_augroup("lazyvim_vimtex_conceal", { clear = true }),
+        pattern = { "bib", "tex" },
+        callback = function()
+          vim.wo.conceallevel = 2
+        end,
+      })
+
+      vim.g.vimtex_mappings_disable = { ["n"] = { "K" } } -- disable `K` as it conflicts with LSP hover
+      vim.g.vimtex_quickfix_method = vim.fn.executable("pplatex") == 1 and "pplatex" or "latexlog"
+    end,
+  },
+
+  -- Correctly setup lspconfig for LaTeX 🚀
+  {
+    "neovim/nvim-lspconfig",
+    optional = true,
+    opts = {
+      servers = {
+        texlab = {
+          keys = {
+            { "<Leader>K", "<plug>(vimtex-doc-package)", desc = "Vimtex Docs", silent = true },
+          },
+        },
+      },
+    },
+  },
+}