Added the full documentation set for the OpenTelemetry filter.
The main README served as the user-facing guide covering build
instructions, core OpenTelemetry concepts, the complete filter
configuration reference, usage examples with worked scenarios,
CLI commands, and known limitations.
Supplementary documents provided a detailed configuration guide with
worked examples (README-configuration), an internal C structure reference
for developers (README-conf), a function reference organized by source
file (README-func), an architecture and implementation review
(README-implementation), and miscellaneous notes (README-misc).
