Add Elixir into 'Language Support' (#5582)

docs/lang-elixir.md

@@ -0,0 +1,43 @@
+# Using WebAssembly from Elixir
+
+Wasmtime [is available on Hex](https://hex.pm/packages/wasmex) and can
+be used programmatically to interact with Wasm modules. This guide will go over
+installing the wasmex package and running a simple Wasm module from Elixir.
+
+## Getting started and simple example
+
+First, copy this example WebAssembly text module into the current directory. It exports
+a function for calculating the greatest common denominator of two numbers.
+
+```wat
+{{#include ../examples/gcd.wat}}
+```
+
+The library has a Rust-based native extension, but thanks to `rustler_precompiled`, you
+should not have to compile anything. It'll just work!
+
+This WAT file can be executed in `iex`:
+
+```elixir
+Mix.install([:wasmex])
+bytes = File.read!("gcd.wat")
+{:ok, pid} = Wasmex.start_link(%{bytes: bytes}) # starts a GenServer running a WASM instance
+Wasmex.call_function(pid, "gcd", [27, 6])
+```
+
+The last command should output:
+
+```elixir
+iex(5)> Wasmex.call_function(pid, "gcd", [27, 6])
+{:ok, [3]}
+```
+
+If this is the output you see, congrats! You've successfully ran your first
+WebAssembly code in Elixir!
+
+## More examples and contributing
+
+To learn more, check out an [another example](https://github.com/tessi/wasmex#example)
+and the [API documentation](https://hexdocs.pm/wasmex/Wasmex.html).
+If you have any questions, do not hesitate to open an issue on the
+[GitHub repository](https://github.com/tessi/wasmex).

docs/lang.md

@@ -11,3 +11,4 @@ through a C API for a number of other languages too:
 * [Go](lang-go.md)
 * [Bash](lang-bash.md)
 * [Ruby](lang-ruby.md)
+* [Elixir](lang-elixir.md)