Option to paginate feed

[wezm]

Some people would prefer that Feedlynx did not trim the feed so that their RSS reader does not have to be relied upon as the source of data. The drawback to this is that feed will grow forever and RSS readers have to fetch and process the whole feed whenever it changes. Trimming helps keep the size of the feed down and number of items the need to be processed.

In #9 (comment) @abhin4v proposed using Atom pagination to handle this:

One option is to keep all the items and add pagination as per https://www.rfc-editor.org/rfc/rfc5005#section-3.

This would allow the main feed to be capped in size but also preserve older items by pushing them to one or more additional files referenced by link elements.

This would probably become the default behaviour when added (since it mean no user data is removed by default) and a new CLI option/env var added to re-enable the existing behaviour of a single feed that gets trimmed.