Add denols to nvim

In Deno projects `tsserver` is less than ideal. This PR starts `denols`
instead of `tsserver` if `nvim` finds the `NVIM_USE_DENOLS` variable
when reading the lsp config.

modules/terminal-life/nvim/lsp.vim

@@ -79,6 +79,8 @@ lua <<EOF
   -- vscode HTML lsp needs this https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#html
   capabilities.textDocument.completion.completionItem.snippetSupport = true
 
+  local use_denols_for_typescript = not(os.getenv('NVIM_USE_DENOLS') == nil)
+
   for lsp_key, lsp_settings in pairs({
         'bashls', ------------------------------- Bash
         'ccls', --------------------------------- C / C++ / Objective-C
@@ -120,7 +122,13 @@ lua <<EOF
         ['terraformls'] = { --------------------- Terraform
             ['filetypes'] = { "terraform", "hcl", "tf" }
         },
-        'tsserver', ----------------------------- Typescript / JavaScript
+
+        -- The TS/JS server is chosen depending on an environment variable,
+        -- since denols is nicer for Deno based projects
+        ------------------------ Deno TS/JS
+        ------------------------------------ Typescript / JavaScript
+        (use_denols_for_typescript and 'denols' or 'tsserver'),
+
         'vuels', -------------------------------- Vue
         'svelte', ------------------------------- Svelte
         ['yamlls'] = { -------------------------- YAML
@@ -204,21 +212,26 @@ lua <<EOF
     },
   }
 
--- Configure diagnostics
-vim.diagnostic.config({
-  virtual_text = false,
-  signs = true,
-  underline = true,
-  update_in_insert = false,
-  severity_sort = false,
-})
+  -- https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#denols
+  vim.g.markdown_fenced_languages = {
+    "ts=typescript"
+  }
 
--- Change diagnostic symbols in the sign column (gutter)
-local signs = { Error = " ", Warn = " ", Hint = " ", Info = " " }
-for type, icon in pairs(signs) do
-  local hl = "DiagnosticSign" .. type
-  vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = hl })
-end
+  -- Configure diagnostics
+  vim.diagnostic.config({
+    virtual_text = false,
+    signs = true,
+    underline = true,
+    update_in_insert = false,
+    severity_sort = false,
+  })
+
+  -- Change diagnostic symbols in the sign column (gutter)
+  local signs = { Error = " ", Warn = " ", Hint = " ", Info = " " }
+  for type, icon in pairs(signs) do
+    local hl = "DiagnosticSign" .. type
+    vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = hl })
+  end
 EOF
 
 " have a fixed column for the diagnostics to appear in