jsdoc: use Jinja2 templates

Pelican also uses Jinja2 templates, so it should be possible to use
same base template base.html

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
nuvolajsdoc: use spaces instead of tabs

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
jsdoc: load configuration from file

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
jsdoc & pelican share common_conf file

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
jsdoc template uses base.html as a parent

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>