There may be several files which contain this error, if you still get this after trying egreg's solution, you can try searching
""Quick start" documentation" and removing the extraneous quotes.
If you still get the error, you could try running
grep -nr '"Quick start"' /usr/local/texlive/2013/tlpkg. This should list any more files with the offending quotes in. Note that some files listed by this command may be backups of earlier files, but it probably doesn't matter too much if you change those as well.
How to use
vim to correct the error
If you are unsure of how to edit the files, try:
sudo vim /path/to/file
Then type the line number, followed by G (such as
127939G in OP's case; the
grep tool should tell you the line numbers of any extra copies if needed). Next, type
i, then use the arrow keys to navigate to the offending quotes and delete them with backspace. Finally, press the escape key, type
:x, and press enter.
If nothing works (last resort)
Firstly, you should try to wait for the new tlmgr update to filter through in case that provides a simple fix in the next few days.
Otherwise, to manually uninstall TeXLive, try the following (make sure this is how it is installed in your machine):
sudo rm -Rf /usr/local/texlive/2013
sudo rm -Rf /usr/local/texlive/texmf-local
This should allow you to reinstall again. Watch out though, when you reinstall TeXLive (depending on the version you downloaded) you may install the
""Quick start" documentation" bug again!
N.B. My tips assume you are running this on a *nix system (UNIX, Linux, OS X, etc).