fix(wording): fixed case of DocSearch (#262)

Author: redox

docs/_includes/join-form.haml

@@ -31,8 +31,8 @@
   %p.text-sm
     %b
       We'll review your request shortly,
-    after making sure your website is eligible to Docsearch.
+    after making sure your website is eligible to DocSearch.
   %p.text-sm
     This is a manual process and can take some time.
   %p.text-sm We'll then email you the code you need to integrate on your website
-  .spacer20
+  .spacer20