📚 Fix rdoc method source styles

Changing `min-content` to `auto` is the big change here.  Also, I'd used
the wrong syntax for `grid-area`, but I didn't need that anyway.

Author: nevans

docs/styles.css

@@ -6,9 +6,7 @@
 
 main .method-detail {
   display: grid;
-  grid-template-areas:   "header         controls"
-                         "description description";
-  grid-template-columns: 1fr           min-content;
+  grid-template-columns: 1fr auto;
   justify-content: space-between;
 }
 
@@ -20,19 +18,16 @@ main .method-header, main .method-controls {
 }
 
 main .method-header {
-  grid-area: "header";
   border-right: none;
   border-radius: 4px 0 0 4px;
 }
 
 main .method-controls {
-  grid-area: "controls";
   border-left: none;
   border-radius: 0 4px 4px 0;
 }
 
 main .method-description, main .aliases {
-  grid-area: "description";
   grid-column: 1 / span 2;
   padding-left: 1em;
 }