Add documentation

Used the following Spoons as a format reference:

- https://github.com/Hammerspoon/Spoons/blob/master/Source/Tunnelblick.spoon/init.lua
- https://github.com/Hammerspoon/Spoons/blob/master/Source/Token.spoon/init.lua

The Spoons documentation describes how to generate a required
`docs.json` file:
https://github.com/Hammerspoon/hammerspoon/blob/master/SPOONS.md

Thanks to Adam Matan (https://stackoverflow.com/users/51197/adam-matan)
on Stack Overflow for the tip on Make's `CURDIR` variable. Didn't know
that existed.
https://stackoverflow.com/questions/52437728/bash-what-is-the-difference-between-pwd-and-curdir/52447088#52447088

3 files changed, 127 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c03d62a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,8 @@
+HS ?= /Applications/Hammerspoon.app/Contents/Resources/extensions/hs/ipc/bin/hs
+
+.PHONY: doc
+doc: docs.json
+
+docs.json: *.lua
+	$(HS) -c "hs.doc.builder.genJSON(\"$(CURDIR)\")" \
+		| grep -v "^--" > $@
diff --git a/docs.json b/docs.json
new file mode 100644
index 0000000..269959e
--- /dev/null
+++ b/docs.json
@@ -0,0 +1,83 @@
+[
+  {
+    "Constant" : [
+
+    ],
+    "submodules" : [
+
+    ],
+    "Function" : [
+
+    ],
+    "Variable" : [
+
+    ],
+    "stripped_doc" : [
+
+    ],
+    "desc" : "Adds a hotkey mode for manipulating windows.",
+    "type" : "Module",
+    "Deprecated" : [
+
+    ],
+    "Constructor" : [
+
+    ],
+    "doc" : "Adds a hotkey mode for manipulating windows.\n\nUpon activating the mode, the following shortcuts are available:\n\nh: Move window left 20 units\nj: Move window down 20 units\nk: Move window up 20 units\nl: Move window right 20 units\n\nShift-h: Move window left 5 units\nShift-j: Move window down 5 units\nShift-k: Move window up 5 units\nShift-l: Move window right 5 units\n\n[: Move window left one screen\n]: Move window right one screen\n\ne: Reduce window height 20 units\ns: Reduce window width 20 units\nd: Increase window height 20 units\nf: Increase window width 20 units\n\nShift-e: Reduce window height 5 units\nShift-s: Reduce window width 5 units\nShift-d: Increase window height 5 units\nShift-f: Increase window width 5 units",
+    "Field" : [
+
+    ],
+    "Command" : [
+
+    ],
+    "items" : [
+      {
+        "doc" : "Bind keys for WindowMode\n\nParameters:\n * mapping – A table containing hotkey modifier\/key details for the following items:\n  * mode – Activate and deactivate window mode",
+        "desc" : "Bind keys for WindowMode",
+        "stripped_doc" : [
+          "Bind keys for WindowMode",
+          ""
+        ],
+        "parameters" : [
+          " * mapping – A table containing hotkey modifier\/key details for the following items:",
+          "  * mode – Activate and deactivate window mode"
+        ],
+        "notes" : [
+
+        ],
+        "signature" : "WindowMode:bindModal(mapping)",
+        "type" : "Method",
+        "returns" : [
+
+        ],
+        "def" : "WindowMode:bindModal(mapping)",
+        "name" : "bindModal"
+      }
+    ],
+    "Method" : [
+      {
+        "doc" : "Bind keys for WindowMode\n\nParameters:\n * mapping – A table containing hotkey modifier\/key details for the following items:\n  * mode – Activate and deactivate window mode",
+        "desc" : "Bind keys for WindowMode",
+        "stripped_doc" : [
+          "Bind keys for WindowMode",
+          ""
+        ],
+        "parameters" : [
+          " * mapping – A table containing hotkey modifier\/key details for the following items:",
+          "  * mode – Activate and deactivate window mode"
+        ],
+        "notes" : [
+
+        ],
+        "signature" : "WindowMode:bindModal(mapping)",
+        "type" : "Method",
+        "returns" : [
+
+        ],
+        "def" : "WindowMode:bindModal(mapping)",
+        "name" : "bindModal"
+      }
+    ],
+    "name" : "WindowMode"
+  }
+]
diff --git a/init.lua b/init.lua
index b6654de..6f6f837 100644
--- a/init.lua
+++ b/init.lua
@@ -1,3 +1,32 @@
+--- === WindowMode ===
+---
+--- Adds a hotkey mode for manipulating windows.
+---
+--- Upon activating the mode, the following shortcuts are available:
+---
+--- h: Move window left 20 units
+--- j: Move window down 20 units
+--- k: Move window up 20 units
+--- l: Move window right 20 units
+---
+--- Shift-h: Move window left 5 units
+--- Shift-j: Move window down 5 units
+--- Shift-k: Move window up 5 units
+--- Shift-l: Move window right 5 units
+---
+--- [: Move window left one screen
+--- ]: Move window right one screen
+---
+--- e: Reduce window height 20 units
+--- s: Reduce window width 20 units
+--- d: Increase window height 20 units
+--- f: Increase window width 20 units
+---
+--- Shift-e: Reduce window height 5 units
+--- Shift-s: Reduce window width 5 units
+--- Shift-d: Increase window height 5 units
+--- Shift-f: Increase window width 5 units
+
 -- Copyright (c) 2019  Teddy Wing
 --
 -- This program is free software: you can redistribute it and/or modify
@@ -31,6 +60,13 @@ obj.spoonPath = script_path()
 
 local window = dofile(obj.spoonPath .. '/window.lua')
 
+--- WindowMode:bindModal(mapping)
+--- Method
+--- Bind keys for WindowMode
+---
+--- Parameters:
+---  * mapping – A table containing hotkey modifier/key details for the following items:
+---   * mode – Activate and deactivate window mode
 function obj:bindHotkeys(keys)
 	local mode = keys['mode']
 	window:bindModal(mode[1], mode[2])