Repo refactor: rename "website" to "docs"

docs/API/slashCommand.md

@@ -0,0 +1,25 @@
+#api/space-lua
+
+APIs to create [[Slash Command]]. For simple cases it is recommended to use [[Library/Std/Infrastructure/Slash Templates]] instead.
+
+## slashCommand.define(spec)
+
+Define a custom slash command.
+
+Supported keys in the spec:
+
+* `name`: name of the command
+* `description`: Description of the command
+* `run`: The callback function that will be invoked once the command is run.
+
+Example:
+
+```lua
+slashCommand.define {
+  name = "hello-world",
+  run = function()
+    editor.insertAtCursor("Hello |^| world!", false, true)
+  end
+}
+```
+