Titles not escaped properly break generation

[leohhhn]

Description

As title says, some titles will break the tutorial generation script:

• This is a `title`
• This is a title()
• Characters disallowed in code, such as &

I propose we introduce a new field in the metadata - a tutorial ID, or slug, which will be unique to the section the tutorial is in, while keeping the title as a normal, quoted string to be displayed on the website.

[alexiscolin]

@leohhhn You must escape this kind of symbols with \
Do you have a wider example of code? My titles works well with your symbols. Maybe I don't see what you mean?