Fix search on ceres-solver.org

Thanks to Roger Labbe for reporting this and Sergiu Deitsch for
debugging it

Change-Id: I7f53b339a1e4d6862b341c60bcf81b77770052bf

docs/source/conf.py

diff --git a/docs/source/conf.py b/docs/source/conf.py
index e206a35..faa2403 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -25,7 +25,7 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.todo', 'sphinx.ext.mathjax', 'sphinx.ext.ifconfig']
+extensions = ['sphinx.ext.todo', 'sphinx.ext.mathjax', 'sphinx.ext.ifconfig', 'sphinxcontrib.jquery']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']

scripts/make_docs.py

diff --git a/scripts/make_docs.py b/scripts/make_docs.py
index 518c319..9eab97e 100644
--- a/scripts/make_docs.py
+++ b/scripts/make_docs.py
@@ -60,7 +60,7 @@
   sphinx_exe = sys.argv[3]
 
 # Run Sphinx to build the documentation.
-os.system('%s -n -b html -d %s %s %s' %(sphinx_exe, cache_dir, src_dir, html_dir))
+os.system('%s -n -a -d %s %s %s' %(sphinx_exe, cache_dir, src_dir, html_dir))
 
 replacements = [
   # The title for the homepage is not ideal, so change it.