README.md extended by analysis of update files

Some clear text information from "update.upd" and "Update3202.upd" have been added
Merge pull request #2 from B-G-T/patch-1

README.md extended by analysis of update files
Check OGG CRC

(this needs hogg installed, run "cabal install hogg")
0xff is also not XORed!

Now the CRC sums are good! Thanks to Matthias Weber for pointing that
out.
XOR findings update
Do not write empty ogg files
Comment out CRC-checking code, to avoid hogg dependency
Ignore broken Ogg Table entries
List working books
Fix markdown syntax
Really Ignore broken Ogg Table entries
List open issues in README
Bauernhof works here now as well
Solve ogg table length
Summarize unknown segments
Update open issues
Name ogg files sequentially, instead of based on offset
Links
The optical code

from https://www.mikrocontroller.net/topic/214479#2973167 by The
Analyzer. This is for TING, but is likely similar for Tip-Toi, as shown
at https://www.mikrocontroller.net/topic/214479#3304870
Clue: Debug strings