[LANG] add basic files for Fish (#968)

lua/lang/fish.lua

@@ -0,0 +1,28 @@
+local M = {}
+
+M.config = function()
+  -- TODO: implement config for language
+  return "No config available!"
+end
+
+M.format = function()
+  -- TODO: implement formatters (if applicable)
+  return "No formatters configured!"
+end
+
+M.lint = function()
+  -- TODO: implement linters (if applicable)
+  return "No linters configured!"
+end
+
+M.lsp = function()
+  -- TODO: implement lsp
+  return "No LSP configured!"
+end
+
+M.dap = function()
+  -- TODO: implement dap
+  return "No DAP configured!"
+end
+
+return M