Added some comments to MP2_scanner.vhd file and copied the bitfile and MP2_scanner.vhd file to the part3 folder. Closes #3

+ I added some basic comments to the MP2_scanner.vhd file (mainly just labeling what ascii character was currently being looked for.
+ I generated and tested the part3 bitfile on hardware. Everything seemed to work to me.
+ I also added the generated exe_Test_echo and exe_Test_gen files to the sw/ folder.