✨feat(reformat-gherkin): added gherkin formatter (cucumber).

[Zeioth]

aka .feature files.

How to test

• Clone this branch.
• Use mason to install reformat-gherkin (filter by cucumber to find it).
• Open a .feature file (examples here)
• If you are using mason-null-ls.nvim, you should see the formatter correctly loaded (botton-right on the image). If not, you can load it manually.
  

Now you can format the code!

More info

• Cucumber is a QA tool.
• Gherkin is the name of the language used by cucumber.
• Gherkin files have the .feature extension.
• Neovim assign the filetype cucumber to .feature files.
• As this is likely to be a mistake, we also support the gherkin filetype.

[mochaaP]

Done in nvimtools/none-ls-extras.nvim@336e84b