add docs for IO

Author: Colin Wahl

docs/04-IO.md

@@ -0,0 +1,47 @@
+# GitHub.Actions.IO
+
+> Core functions for cli filesystem scenarios
+
+This module exposes bindings to the [@actions/io package](https://github.com/actions/toolkit/tree/main/packages/io).
+
+## Usage
+
+#### mkdir -p
+
+Recursively make a directory. Follows rules specified in [man mkdir](https://linux.die.net/man/1/mkdir) with the `-p` option specified:
+
+```purescript
+IO.mkdirP { fsPath: "path/to/make" }
+```
+
+#### cp/mv
+
+Copy or move files or folders. Follows rules specified in [man cp](https://linux.die.net/man/1/cp) and [man mv](https://linux.die.net/man/1/mv):
+
+```purescript
+// Recursive must be true for directories
+const options = { recursive: true, force: false }
+
+let copyOptions = { recursive: Just true, foce: Just false }
+
+IO.cp { source: "path/to/directory", dest: "path/to/dest", options: Just copyOptions }
+IO.mv { source: "path/to/file", dest: "path/to/dest" }
+```
+
+#### rm -rf
+
+Remove a file or folder recursively. Follows rules specified in [man rm](https://linux.die.net/man/1/rm) with the `-r` and `-f` rules specified.
+
+```purescript
+IO.rmRF { inputPath: "path/to/directory" }
+```
+
+#### which
+
+Get the path to a tool and resolves via paths. Follows the rules specified in [man which](https://linux.die.net/man/1/which).
+
+```purescript
+example = do
+  pythonPath <- IO.which' "python"
+  Exec.exec { command: pythonPath, args: Just [ "main.py" ], options: Nothing }
+```