feat: add styler formatter for R (#184)

* feat: add styler formatter for R

* fix: do not run --vanilla to pick up options

* docs: add to README

* fix: std in false

* fix: do not hardcode style, use config file

* fix: lint styler formatter

README.md

@@ -257,6 +257,7 @@ You can view this list in vim with `:help conform-formatters`
 - [standardjs](https://standardjs.com) - JavaScript Standard style guide, linter, and formatter.
 - [standardrb](https://github.com/standardrb/standard) - Ruby's bikeshed-proof linter and formatter.
 - [stylelint](https://github.com/stylelint/stylelint) - A mighty CSS linter that helps you avoid errors and enforce conventions.
+- [styler](https://github.com/devOpifex/r.nvim) - A formatter for the R programming language.
 - [stylua](https://github.com/JohnnyMorganz/StyLua) - An opinionated code formatter for Lua.
 - [swift_format](https://github.com/apple/swift-format) - Swift formatter from apple. Requires building from source with `swift build`.
 - [swiftformat](https://github.com/nicklockwood/SwiftFormat) - SwiftFormat is a code library and command-line tool for reformatting `swift` code on macOS or Linux.

lua/conform/formatters/styler.lua

@@ -0,0 +1,11 @@
+local util = require("conform.util")
+---@type conform.FileFormatterConfig
+return {
+  meta = {
+    url = "https://github.com/devOpifex/r.nvim",
+    description = "R formatter and linter.",
+  },
+  command = util.find_executable({ "usr/bin/" }, "R"),
+  args = { "-s", "-e", "r.nvim::format()", "--args", "$FILENAME" },
+  stdin = false,
+}