elixir.json: Add "df" and "dfw" for one-liner functions (#519)

* elixir.json: Add "df" and "dfw" for one-liner functions (with when guard)

Author: multivac61

snippets/elixir.json

@@ -14,6 +14,16 @@
         "body": ["defp ${1:name}() do", "  $0", "end"],
         "description": "Define a private function"
     },
+    "df": {
+        "prefix": "df",
+        "body": "def ${1:name}(), do: $0",
+        "description": "Define a one-liner function"
+    },
+    "dfw": {
+        "prefix": "dfw",
+        "body": "def ${1:name}(${2:args}) when ${3:guard}, do: $0",
+        "description": "Define a one-liner function with when guard"
+    },
     "IO.puts": {
         "prefix": "put",
         "body": "IO.puts($0)"