Correct an example variable name

[ThinkOpenly]

In "Vectors", there is this example:

let a_generic_vector : vector(3, bit) = [bitzero, bitzero, bitone]
let a_bit_vector : bits(3) = [bitzero, bitzero, bitone] // 0b001

assert(a_generic_vector[0] == bitone)
assert(a_bitvector_vector[0] == bitone)

Note how the declaration of a_bit_vector does not match its use: a_bitvector_vector. Fix this by using a_bitvector for both.

[Alasdair]

Thanks, the HTML is generated using Asciidoc, so I fixed the source here https://github.com/rems-project/sail/pull/601