feat: add support for ltex-ls

Co-authored-by: William Boman <william@redwill.se>

lua/lspconfig/ltex.lua

@@ -0,0 +1,37 @@
+local configs = require 'lspconfig/configs'
+local util = require 'lspconfig/util'
+
+configs.ltex = {
+  default_config = {
+    cmd = { "ltex-ls" },
+    filetypes = { "tex", "bib", "markdown" },
+    root_dir = util.find_git_ancestor,
+    settings = {
+      ltex = {
+        enabled = { "latex", "tex", "bib", "markdown" },
+        checkFrequency = "edit",
+        language = "en",
+        diagnosticSeverity = "information",
+        setenceCacheSize = 2000,
+        additionalRules = {
+          enablePickyRules = true,
+          motherTongue = "en",
+        },
+        dictionary = {},
+        disabledRules = {},
+        hiddenFalsePositives = {},
+      },
+    },
+  },
+  docs = {
+    package_json = "https://raw.githubusercontent.com/valentjn/vscode-ltex/develop/package.json",
+    description = [[
+https://github.com/valentjn/ltex-ls
+
+LTeX Language Server: LSP language server for LanguageTool 🔍✔️ with support for LaTeX 🎓, Markdown 📝, and others
+
+To install, download the latest [release](https://github.com/valentjn/ltex-ls/releases) and ensure `ltex-ls` is on your path.
+
+]],
+  },
+}