Add key bindings wiki link to README

Author: osa1

README.md

@@ -129,6 +129,11 @@ You can use `--config <path>` to specify your config file location.
 
 ## Key bindings
 
+Key bindings can be configured in the config file, see the [wiki
+page][key-bindings-wiki] for details.
+
+Default key bindings:
+
 - `C-a`/`C-e` move cursor to beginning/end in the input field
 
 - `C-k` delete rest of the line
@@ -153,6 +158,8 @@ You can use `--config <path>` to specify your config file location.
 
 - `C-x` edit current message in `$EDITOR`
 
+[key-bindings-wiki]: https://github.com/osa1/tiny/wiki/Configuring-key-bindings
+
 ## Commands
 
 Commands start with `/` character.