remove leftover ABNF description from initial RainerScript idea

Long replaced left-over from the initial design phase years ago.
rainerscript: remove old cruft
Merge pull request #33 from rgerhards/v5-stable-remove-rs-abnf

V5 stable remove rs abnf
Added the formatting changes for templates.rst added by so14k
clean up old cruft regarding rsyslog packages
install toc: move more important things first
add "outdated" warning
move outdated section to bottom
Merge pull request #38 from rgerhards/v5-stable-modules

V5 stable -- warn about outdated doc
Merge pull request #36 from rgerhards/v5-stable-install

V5 stable install
remove totally outdated contributor list

see also: https://github.com/rsyslog/rsyslog-doc/issues/43
Merge pull request #48 from rgerhards/v5-stable-contributors

remove totally outdated contributor list
Re-added image files that had been corrupted.
Replaced corrupt image.
Merge branch 'v5-stable' into v5-stable-restructure
remove outdated "bugs" listing

This has long been superseeded by the bug trackers
see also: https://github.com/rsyslog/rsyslog-doc/issues/42