lynx-dev documentation update

[Leonid Pauzner]

Please clean po/ChangeLog - it is not valid now.
Also, add po/readme as follows:

----- cut here ----------

> I want to translate to xxxxxx.

The full list of messages is in lynx.pot, which is generated from looking
at the calls to gettext, use it as template for translations.

syntax:

#: src/LYMainLoop.c:1512 src/LYMainLoop.c:1516
msgid "Fatal error - could not open output file %s\n"
msgstr ""

First line is a comment beginning with #, for your information.
Original english string is <msgid>, do not change it.
Translation in <msgstr>, empty string assume english default.
Do not forget to include %s properly in you contributed translation!

A good place to start is with the messages derived from LYMessages_en.h

> Cheers..