feature request: customize badge label

[waldyrious]

For example in tldr-pages/tldr we're using the file count badge as a proxy to the number of pages in the collection. Ideally we'd want to only count files in the pages directory (#124), but even with the current count, which is already a good approximation, we'd want to change the label from "Files" to "pages".

More generally, I think the label should be lowercased to match the majority of default badge labels (see e.g. https://shields.io)

[XAMPPRocky]

@waldyrious Hello the code for tokei_rs has been made public can you please move the issue over to it. https://github.com/Aaronepower/tokei_rs