[css-shadow-parts-1] fix several typos

Author: fergald

css-shadow-parts-1/Overview.bs

@@ -42,7 +42,7 @@ into the component for it to do with as it will,
 these pseudo-elements allow components and the outside page
 to interact in safe, powerful ways,
 maintaining encapsulation
-without surrending all control.
+without surrendering all control.
 
 Motivation {#motivation}
 ------------------------
@@ -192,7 +192,7 @@ not an id or tagname.
 </template>
 <c-e></c-e>
 <script>
-  // Add template as custom elment c-e
+  // Add template as custom element c-e
   ...
 </script>
 </pre>
@@ -217,7 +217,7 @@ Each part mapping is one of:
     :: Is shorthand for <code>ident : ident</code>.
 
     : anything else
-    :: Ignored for error-recovery / future compat.
+    :: Ignored for error-recovery / future compatibility.
 </dl>
 
 Note: It's okay to map a sub-part to several names.
@@ -256,7 +256,7 @@ Consider a mechanism to exclude sub-parts without forwarding them.
 
 &lt;c-e&gt;&lt;/c-e&gt;
 &lt;script&gt;
-  // Add template as custom elments c-e-inner, c-e-outer
+  // Add template as custom elements c-e-inner, c-e-outer
     ...
 &lt;/script&gt;
 </pre>