update link to Etienne's slides

Etienne is changing the slides, when they are finished, we need to update the different links in Assignements.

• TC-1
• TC-2
• TC-3
• TC-4
• TC-5
• TC-6
• TC-7
• TC-8
• TC-9
• TC-E
• TC-A
• TC-R
• TC-Y
• TC-X
• Source Code: lib/misc, File: symbol.*