Turn exercices 033 to 042 into practice

[cuihtlauac]

This task consists of doing 9 exercises instead of one, as described in issues #2167, #2168, #2170, #2172, #2173, #2176, #2177, #2178, #2179 and #2180. Create 10 folders (from 033 to 042), and populate them as the others. Makes sure dune build --root . and dune test --root . answer work.

• 033 Turned exercise 033 into practice #2220
• 034 Turned exercise 034 into practice #2221
• 035 Turned exercise 035 into practice #2222
• 036 Turned exercise 036 into practice #2223
• 037 Turned exercise 037 into practice #2245
• 038 Merge 038 into 037 #2248
• 039 Turned exercise 039 into practice #2281
• 040 Turned exercise 040 into practice #2283
• 041

[MissJae]

Can I do this? @cuihtlauac

[maha-sachin]

@cuihtlauac, can you help me to assign this issue?

[cuihtlauac]

@MissJae

Can I do this? @cuihtlauac

Complete #2192 first