feat(erlang): Add Erlang module (#1129)

docs/config/README.md

@@ -105,6 +105,7 @@ prompt_order = [
     "dotnet",
     "elixir",
     "elm",
+    "erlang",
     "golang",
     "haskell",
     "java",
@@ -521,6 +522,29 @@ The module will be shown if any of the following conditions are met:
 symbol = " "
 ```
 
+## Erlang
+
+The `erlang` module shows the currently installed version of Erlang/OTP.
+The module will be shown if any of the following conditions are met:
+
+- The current directory contains a `rebar.config` file.
+- The current directory contains a `erlang.mk` file.
+
+### Options
+
+| Variable   | Default | Description                                                     |
+| ---------- | ------- | --------------------------------------------------------------- |
+| `symbol`   | `"🖧 "` | The symbol used before displaying the version of Erlang. |
+| `disabled` | `false` | Disables the `erlang` module.                                   |
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[erlang]
+symbol = "e "
+```
 ## Environment Variable
 
 The `env_var` module displays the current value of a selected environment variable.