[i18n] How to adapt help.xml files

[Otto Stolz]

Hello,

how can I adapt the help files to my local environment?
E. g., I'd like to add to the compose-attach entry in
imp/locale/en_US/help.xml a note about the maximum
size of an attached file.

I have found the help.xml files, but I have not found
any documentation about their syntax.

Of course, I can mimick the entry, and para, tags
from the examples in imp/locale/en_US/help.xml,
but I'd rather see the whole picture. E. g.:
- Which HTML entities can I use?
   Apparently, " " will break the help system,
   whilst """ is used, extensively.
- Can I point to further reading, such as our FAQ
   or our terms of service (both available via HTTP)?
- What tags are possible, and what is their respective
   syntax and meaning?
   Apparently, <cite> is without effect.

So, if there is any documentation anywhere, please
point me to it.

Best wishes,
   Otto Stolz