zshrc: New prompt: Keep maps sorted

Signed-off-by: Frank Terbeck <ft@grml.org>
zshrc: New prompt: Documentation update

Signed-off-by: Frank Terbeck <ft@grml.org>
grmlzshrc.t2t: Document the new prompt themes

Signed-off-by: Frank Terbeck <ft@grml.org>
grmlzshrc.t2t: Update copyright years

Signed-off-by: Frank Terbeck <ft@grml.org>
zshrc: New prompt mixed up %B and %b for the path item