Add support for displaying most used language (or 2nd, 3rd, 4th, ...)

[elliotwutingfeng]

Closes #87

Continues where #96 left off. Thank you @spenserblack for starting this.

Display the n-th most used language by enabling ?showLanguage=true and using the ?languageRank=n query string, where n ∈[1, number of languages detected by tokei]

For example,

https://tokei-rs.onrender.com/b1/github/XAMPPRocky/tokei?showLanguage=true&languageRank=1&label=Champion&style=for-the-badge)](https://github.com/XAMPPRocky/tokei

Edge cases

• If ?showLanguage=true is not present, line count will be displayed as per default badge behavior.
• If ?showLanguage=true but ?languageRank= not present, badge will display most used language.
• If n ∉[1, number of languages detected by tokei], badge will display "N/A".
• If no languages are detected by tokei, badge will display "No Language".

Live Demo

Repo: https://github.com/XAMPPRocky/tokei

Colors, badge styles, logos, and labels can be freely customized by the user.

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It is possible to enable negative integers and get least-used, 2nd least used languages, ..., but this would probably be out of scope here.

Is ranking a suitable query parameter name?

[spenserblack]

Thanks for doing this! Reusing the same endpoint and adding some more query parameters makes the code look much more elegant than what I was doing 😆

Is ranking a suitable query parameter name?

Just an idea for slightly more clear usage:
The endpoint showing lines-of-code by default, and the name of a language with ?ranking=1 might be a bit confusing IMO. A boolean parameter like ?getLanguage might be more clear. You could be strict and check if the paremeter == "true", or perhaps you can just check if the parameter exists in the query parameters. When this is used, by default ranking=1. This could potentially make the ranking parameter a bit more clear -- it's the ranking for getLanguage. And this way ranking has a singular purpose, to get the nth language, and doesn't have the additional purpose of being a flag to display the language name.

Values passed to ?ranking= will be capped at number of languages detected by tokei. For example, if tokei detects 6 languages in a repo, and ?ranking=300 is specified, 300 will be capped to 6.

This might make sense where the number of languages is known, but might be a bit awkward when the number of languages is unknown and/or frequently change. Might make more sense for out-of-bounds language rankings to simply be N/A. For example, if I wanted to display the top n languages of a project, and the actual number of languages went from >= n to < n, it might be inconvenient if the badges started to look like this: 1st: Lang1, 2nd: Lang2, ..., (n-1)th: LastLang, nth: LastLang. This would require action on my part to delete one or more badges to make the results make more sense, while N/A for out-of-bounds rankings could be left alone and still look "clean."

[XAMPPRocky]

Thank you for your PR! Sorry for the delay, but now that I merged your other PR, this has conflicts. Would you be interested in updating this one?

[elliotwutingfeng]

Haven't looked into this for a while, will try deploying on onrender.com

[XAMPPRocky]

Thank you for your PR!