Remove duplicate intro text in touristic-autism guides
Problem
The same intro paragraph appears in 10 touristic-autism_*.md files:
"The basic guides that have been merged and adapted are the [Ruby on Rails Tutorial]..."
Solution
Create a shared include file and replace duplicates with {% include touristic-autism-intro.md %}.
Files to update
- touristic-autism_basic-app.md
- touristic-autism_continuous-deployment.md
- touristic-autism_design.md
- touristic-autism_git.md
- touristic-autism_google-map.md
- touristic-autism_image-upload.md
- touristic-autism_intro.md
- touristic-autism_resource-modeling.md
- touristic-autism_resource-rating.md
- touristic-autism_static-pages-tdd.md