[tex-hyphen] top-level comment typos

[Karl Berry]

I happened to look at one of the generated hyph-utf8 files today
(hyph-pt.tex though I assume they're all the same) and have a couple
trivial typo fixes for the intro text:

should preferaby modify -> should preferably modify

Modificatios were needed -> Modifications were needed

did the unicodifisation -> unicodification

taking over a new revolution ... not sure what's intended.
starting a new revolution?  taking over maintenance of this file?


(Obviously no need to re-upload anything for this.  Are there any "real"
changes pending for TL'15?)

best,
k