Add documentation for static/typable/macro commands

book/src/remapping.md

@@ -75,5 +75,20 @@ Ctrl, Shift and Alt modifiers are encoded respectively with the prefixes
 
 Keys can be disabled by binding them to the `no_op` command.
 
-A list of commands is available in the [Keymap](https://docs.helix-editor.com/keymap.html) documentation
+## Commands
- and in the source code at [`helix-term/src/commands.rs`](https://github.com/helix-editor/helix/blob/master/helix-term/src/commands.rs) at the invocation of `static_commands!` macro and the `TypableCommandList`.
+
+There are three kinds of commands that can be used in keymaps:
+
+* Static commands: commands like `move_char_right` which are usually bound to
+  keys and used for movement and editing. A list of static commands is
+  available in the [Keymap](./keymap.html) documentation and in the source code
+  in [`helix-term/src/commands.rs`](https://github.com/helix-editor/helix/blob/master/helix-term/src/commands.rs)
+  at the invocation of `static_commands!` macro and the `TypableCommandList`.
+* Typable commands: commands that can be executed from command mode (`:`), for
+  example `:write!`. See the [Commands](./commands.html) documentation for a
+  list of available typeable commands.
+* Macros: sequences of keys that are executed in order. These keybindings
+  start with `@` and then list any number of keys to be executed. For example
+  `@miw` can be used to select the surrounding word. For now, macro keybindings
+  are not allowed in keybinding sequences due to limitations in the way that
+  command sequences are executed.