Fix trivial typos in text

Found using

    codespell -q 3 --skip="./Utilities" -I .cmake-whitelist.txt`

in CMake whereby the whitelist contained:

    ans
    dum
    helpfull
    emmited
    emmitted
    buil
    iff
    isnt
    nto
    ot
    pathes
    substract
    te
    todays
    upto
    whitespaces