Fix links to glossary

@r-gaia-cs brokes some links with #394. This fix this links.

~~~
$ for i in $(grep -rl '../../../gloss.html' novice)
do sed -i 's@../../../gloss@../../gloss@' $i
done
$ grep -re '../../../gloss.html' novice
$ grep -re '../../../gloss.html' intermediate
~~~

Thanks to @lexnederbragt.