This commit fixes some cross-doc links from the old ingest plugins page
to the new ingest processor pages that arose after converting
ingest-geoip and ingest-user-agent to modules.
This commit adds a placeholder ingest-geoip plugin page as there are
other components in the Elastic Stack that still refer to these
pages. These docs would be broken without this placeholder page forcing
teams responsible for those docs to scramble to fix the build over the
weekend before a holiday period. Instead, we add a placeholder page so
the docs build continues to function, and those teams can fix their docs
without the constraint of a broken build. We also cleanup a few minor
docs issues that were missed during the initial changes to convert
ingest-geoip to a module.
This commit breaks the single ingest docs file into multiple files,
factoring out the processor docs into a documentation file per
processor. This will help make this content easier to maintain.
Jason Tedor