Add more information to release notes about event filtering

[peterfpeterson]

Adds clarifying comments about arithmetic statistics and how values are deleted from logs.

To test:

Review the release notes

Refs #34794.

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[sf1919]

I've looked over the text and that looks ok - although generally the release notes have unnumbered bullet point lists unless there is a very specific reason to number them.

I did build the page and the links work. However there was a warning given that probably needs to be resolved.
release/v6.7.0/framework:2: WARNING: Bullet list ends without a blank line; unexpected unindent.

[peterfpeterson]

I changed the enumeration to a bulleted list and fixed a minor issue with a different doc. The warning you point out comes from how the "amalgamate" command works

[sf1919]

Thanks for changing to a bullet point list. The documentation warnings need to be dealt with but they go beyond just this release note and so I've raised it separately (#35473).