Update 0002-intrinsics-memory.md (rust-lang#209)

Fixing typos.

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Co-authored-by: Carolyn Zech <[email protected]>

Author: ReinierMaas

doc/src/challenges/0002-intrinsics-memory.md

@@ -61,7 +61,7 @@ All the following usages of intrinsics were proven safe:
 
 
 
-Annotate and verify all the functions that below that expose intrinsics with safety contracts
+Annotate and verify all the functions below that expose intrinsics with safety contracts
 
 | Function | Location |
 |---------|---------|