fix typo 'let' to 'left' in jquery.terminal.css

 this typo caused a warning in css minification

Author: rikkarth

css/jquery.terminal.css

@@ -23,11 +23,11 @@
 }
 .cmd .cmd-clipboard {
     position: absolute !important;
-    let: -16px;
+    left: -16px;
     left: calc(-16px / var(--pixel-density, 1)) !important;
     top: 0 !important;
     width: 16px;
-    height: 16px;
+    height: 16px; fix typo 'let' to 'left' in jquery.terminal.css 
     width: calc(16px / var(--pixel-density, 1)) !important;
     height: calc(16px / var(--pixel-density, 1)) !important;
     background: transparent !important;