fix(index): keep page parameters visible after submit

By switching the form method to get the url will now have all paramters necessary in order to share the search results.
The search works as before including the

Example:
Entering "file:" in the search box and hitting the "Search" button
- URL Before
   http://localhost:8080/exist/apps/fundocs/index.html?
- URL After
   http://localhost:8080/exist/apps/fundocs/index.html?q=file%3A&action=search&type=name

Author: line-o

src/main/xar-resources/index.html

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <div data-template="templates:surround" data-template-with="templates/page.html" data-template-at="main">
     <h1>XQuery Function Documentation</h1>
-    <form id="fun-query-form" name="f-query" class="form-horizontal" action="?" method="POST">
+    <form id="fun-query-form" name="f-query" class="form-horizontal" action="?" method="GET">
         <div class="row mb-3">
             <label class="col-form-label col-md-2 hidden-xs">Search</label>
             <div class="col-md-4 col-xs-12">