elixir: add page (#4693)

pages/common/elixir.md

@@ -0,0 +1,12 @@
+# elixir
+
+> Elixir programming language interpreter.
+> More information: <https://elixir-lang.org>.
+
+- Run an Elixir file:
+
+`elixir {{path/to/file}}`
+
+- Evaluate Elixir code by passing it as an argument:
+
+`elixir -e "{{code}}"`