better wording for the joypad mappings

README.md

@@ -35,7 +35,7 @@ The only core option available on the frontend is:
 * Emulate Chroma 81 (auto|disabled|enabled): Enable the [Chroma 81](http://www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface.htm) interface
 * Video Presets (clean|tv|noisy): Change how the video is emulated (if Chroma 81 is enabled, the video is set to "clean" regardless of this option)
 * Sound emulation (auto|none|Zon X-81): Enables sound emulation
-* Joypad button mappings (up, down, left, right, a, b, x, y, l, r, l2, r2): (auto|default|new line|shift|space|.|0|1|2|3|4|5|6|7|8|9|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z): Maps a joypad button to a keyboard key, defaults are the cursor keys for the directional pad and '0' to all the other buttons
+* Joypad button (up, down, left, right, a, b, x, y, l, r, l2, r2) mappings (auto|default|new line|shift|space|.|0|1|2|3|4|5|6|7|8|9|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z): Maps a joypad button to a keyboard key, defaults are the cursor keys for the directional pad and '0' to all the other buttons
 * Transparent Keyboard Overlay (enabled|disabled): If the keyboard overlay is transparent or opaque
 * Time to Release Key in ms (500|1000|100|300): How many milliseconds to wait before releasing the key pressed using the keyboard overlay