Correct typo (#1832)

Signed-off-by: David Harris <[email protected]>

src/vector-crypto.adoc

@@ -2614,7 +2614,7 @@ The NIST specification (see <<zvkg>>) orders the coefficients from left to right
 for a polynomial x~0~ + x~1~u +x~2~ u^2^ + ... + x~127~u^127^. This can be viewed as a collection of
 byte elements in memory with the byte containing the lowest coefficients (i.e., 0,1,2,3,4,5,6,7)
 residing at the lowest memory address. Since the bits in the bytes are reversed, 
-This instruction internally performs bit swaps within bytes to put the bits in the standard ordering
+this instruction internally performs bit swaps within bytes to put the bits in the standard ordering
 (e.g., 7,6,5,4,3,2,1,0).
 
 This instruction must always be implemented such that its execution latency does not depend