more flexible prerequisite management

* Move external <link>s and <script>s into separate includes.
* Opt for minified versions of external CSS stylesheets and JavaScript
files by default, allowing to use the properly formatted versions during
development using _config_dev.yml.
* External components versions are now in the config file.

1 files changed, 5 insertions, 0 deletions

diff --git a/_includes/jquery.html b/_includes/jquery.html
new file mode 100644
index 0000000..aa6d2fd
--- /dev/null
+++ b/_includes/jquery.html
@@ -0,0 +1,5 @@
+{% if site.minified_externals %}
+  <script src="https://code.jquery.com/jquery-{{ site.jquery_version }}.min.js"></script>
+{% else %}
+  <script src="https://code.jquery.com/jquery-{{ site.jquery_version }}.js"></script>
+{% endif %}