Configurable file size limits
Included in v0.0.20
Historically, check-spelling would check any file it could open.
Some repositories have giant files.
Whether they're actually text files isn't relevant to check-spelling, unless they're excluded, it would process them.
Default is to exclude files over 1 mb.
Files that are too large will be suggested for exclusion.
I might also want to have check-spelling time itself and warn when it takes too long to scan a file. -- This would also be configurable.