New screencasts wiki subtitles pages

[stephen]

I've started to create some new pages in the screencasts wiki about the
process and tools used to make subtitles, using the screencasting pages
as a template. Hopefully someone will find them useful. Please feel free
to expand and refine.
https://wiki.ubuntu.com/ScreenCasts/Subtitles

After reading Alan's recent blog post
http://popey.com/Multi-lingual_Video_and_Audio, I'm not yet sure what we
are going to do with the files after creation, but this should help us
get started.

Steve