fix typo

Author: keithamus

docs/index.html

@@ -155,7 +155,7 @@ <h1>GitHub Feature Support Table</h1>
             </p><p>
               <span class="polyfilled">*</span>Not avaible in this browser, but polyfilled using this library.
             </p><p>
-              <span class="buggy"><small>†</small></span>Required feature, buy polyfilled to smooth over bugs in this browser.
+              <span class="buggy"><small>†</small></span>Required feature, but polyfilled to smooth over bugs in this browser.
             </p><p>
               <span class="transpiled">**</span>Not available in this browser, but transpiled to a compatible syntax.
             </p>