fix blockquote font size

The blockquote font size is 17.5px in bootstrap where normal text is
14px. This is because blockquote is thought of for doing pull
quotes. However sphinx uses block quote for indented text, and it
should thus be the same as the body text.

Part of bp:api-ref-in-rst

Change-Id: I4135686416d84f5ca113a031534c3486a4c2b1c5

api-ref/source/_static/api-site.css

@@ -7,6 +7,10 @@ tt.literal {
     border-radius: 4px;
 }
 
+/* bootstrap users blockquote for pull quotes, so they are much
+larger, we need them smaller */
+blockquote { font-size: 1em; }
+
 pre {
     display: block;
     padding: 9.5px;