SQL Injection

[ocaml-n00b]

Not sure if you would be interested but I've added sql injections with SQLite and added a nav.html file that is loaded by all other pages (using php) to make it more easy to add new challenges moving forward.
The changes can be summarized as follows:

• Changed most aX.html files to php in order to add an easy to modify nav.html for adding more challenges.
• Added SQLite installation to the docker file.
• Added SQLite DataBase.
• Added an SQL injection challenge.
• Renamed files for consistency.
• Modified relevant files to reflect changes made.
• Tested new Docker container

If interested let me know so I can issue a pull request!