use our own custom Jekyll-Multiple-Languages-Plugin

[plowsof]

prefacing this by saying i don't know what ruby or gems are.

please read 2140 for more context:

• #2140

we are currently forced to use ruby < 3.2.0 which is not good for long term as Ruby EOL's versions frequently

Starting in Ruby 3.2.0 the exists? (pluralized) alias for exist? seems to has been removed.

• Jekyll multiple language (JML) plugin has an "exists?" which can be simply fixed, just like in this upstream PR but its not maintained anymore.

• we also have an "exists?" to be replaced with "exist?" here https://github.com/monero-project/monero-site/blob/99fd539bea6b819ce1a3a02722d3062cf6f18fc6/_plugins/sitemap_generator.rb#L129

• we're using JML version 1.7.0 but there is a 1.8.0 version that has an error reg parsing a nul string, which is either another dependency issue (paginate) or fixable if we can modify JML ourselves: no implicit conversion of nil into String since 1.8.0

Now to my request. So before i can even attempt to fix the lowest hanging fruit "exists?" -> "exist?" issue, i need to use/import a custom version of JML.

Jekyll multiple languages plugin describes how to import/use the plugin manually (or as a submodule): https://github.com/kurtsson/jekyll-multiple-languages-plugin?tab=readme-ov-file#32-manually

I couldn't get it to work.. infinite recursion.. dependency still attempted to be grabbed from an external resource instead of locally. I am hoping its just my lack of ruby/gem/plugin knowledge and someone can help/advise.