longer auto meta descriptions

[cnb]

It seems that google is now accepting longer descriptions, up to 320 chars (instead of 160 or so)
https://searchengineland.com/google-officially-increases-length-snippets-search-results-287596

Note: NM currently only generates the post's meta description automatically if custom setting autometad is enabled, as an excerpt of 150 chars max. (#31)

also related: GS repo issue 1240

[cnb]

Not sure about this. Perhaps for automatic meta descriptions it's better they're short, as we're just duplicating content. I'll revert this to 150 chars for now.

Custom meta descriptions (#255), however, will not have a limit.

[cnb]

d57d64a