docs: update note on transport proto for oversized messages with RFC6313

Signed-off-by: Alexander Bartolomey <github@alexanderbartolomey.de>

docs: add proper README

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

docs: update formatting in package overview

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

docs: add more documentation for package overview and examples

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

chore!: drastically reduce public surface of a lot of unneeded types

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

feat: add IPFIXFileReader for consuming files (RFC 5655)

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

feat: add etcd FieldCache and TemplateCache implementation

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

refactor: export FromContext to use in etcd submodule

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>

feat!: publish package

examples and refined documentation will be added later, as well as some TODOs leftover from the private
codebase this was factored out from.

Signed-off-by: Alexander Bartolomey <occloxium@gmail.com>