add search bar

close #40

src/README.org

@@ -2,6 +2,11 @@
 #+PROPERTY: comments org
 #+SETUPFILE: ../docs/theme.setup
 
+#+BEGIN_EXPORT html
+<script async src="https://cse.google.com/cse.js?cx=a67f8ab65a66f97f2"></script>
+<div class="gcse-search"></div>  
+#+END_EXPORT
+
 ------------------
 
    - [[./tutorial_benzene.html][Tutorial]]

tools/build_doc.sh

@@ -123,6 +123,11 @@ function main() {
     then
         cd ${DOCS}
         rm -f index.html
+	# enter Google verificator into the HTML head
+        local GOOGLE_VERIF="<meta name="google-site-verification" content="jdDnuP2rYGJVy8AHSd-8LkmOmvK_dyz5buZ98wilYII" />"
+        LINE_NO=$(($(awk '/meta name="viewport"/{print NR}' README.html) + 1))
+        sed -i "$LINE_NO i ${GOOGLE_VERIF}" README.html
+        
 	ln README.html index.html
         exit 0
     else