[tldoc] TL20 and top-level README

[Karl Berry]

Hello all TeX Live translators - we are a few weeks away from pretest
for the 2020 release.

If you handled the translation last year, please tell me if you'll be
able to do it again this year. If not, no problem of course, I'd just
like to know so we can try to find other volunteers.

I hope to have the main TL manual ready for translation updates by the
end of February or so.

For right now ... I just made a couple small changes to the top-level
README, that is, readme-html.dir/readme.en.html and
readme-txt.dir/README.EN. 
This tiny doc file is not year-dependent, so updates to the translation
now are welcome.

It's fine to either commit them yourself or email them to me, but if you
email them, please send me a .zip or .tar.gz, otherwise there will be
encoding problems.

I'll attach the diffs. The original files (for all languages) can be
found here:
  http://tug.org/svn/texlive/trunk/Master/readme-html.dir/
  http://tug.org/svn/texlive/trunk/Master/readme-txt.dir/

By the way, I created the text file from the html using lynx, to avoid
making the same edits twice. My script is here:
  http://tug.org/svn/texlive/trunk/Master/tlpkg/bin/htmltext
Feel free to use it, or the equivalent. Whatever works for you, of course.
--thanks, karl.