suffix is the text that comes after the insertion point.
So if you have in the playground something like
line1
[insert]
line2
in the API, it would become
prompt: line1
suffix: line2
suffix is the text that comes after the insertion point.
So if you have in the playground something like
line1
[insert]
line2
in the API, it would become
prompt: line1
suffix: line2