add contribution section to README, add .stylua.toml for formatting

.stylua.toml

@@ -0,0 +1,5 @@
+column_width = 120
+line_endings = "Unix"
+indent_type = "Spaces"
+indent_width = 2
+quote_style = "ForceDouble"

README.md

@@ -29,6 +29,12 @@ require('telescope').load_extension('env')
 # Usage
 `:Telescope env`
 
+# Contribution
+If you have any idea to improve this project, please create a pull-request for it. To make changes consistent, i have some rules for PRs:
+1. Before submit your work, please format it with [StyLua](https://github.com/JohnnyMorganz/StyLua).
+  1.1. I provided an __.stylua__ file in root of the project. Just call: `stylua lua/telescope/_extensions/env.lua`
+2. There should be a one-to-one relation between features and pull requests. Please create separate pull-requests for each feature.
+
 # Roadmap :blue_car:
 - [ ] copy selected value when select an item in picker.
 - [ ] use previews because some variables like `PATH` don't fit on screen.

lua/telescope/_extensions/env.lua

@@ -1,13 +1,13 @@
-local pickers = require "telescope.pickers"
-local finders = require "telescope.finders"
-local actions = require "telescope.actions"
+local pickers = require("telescope.pickers")
+local finders = require("telescope.finders")
+local actions = require("telescope.actions")
 local conf = require("telescope.config").values
-local entry_display = require('telescope.pickers.entry_display')
+local entry_display = require("telescope.pickers.entry_display")
 
 local function prepareEnvironmentVariables()
   Items = {}
   for key, value in pairs(vim.fn.environ()) do
-    table.insert(Items, {key, value})
+    table.insert(Items, { key, value })
   end
   return Items
 end
@@ -16,14 +16,11 @@ local function showEnvironmentVariables(opts)
   opts = opts or {}
   pickers.new(opts, {
     prompt_title = "Environment Variables",
-    finder = finders.new_table {
+    finder = finders.new_table({
       results = prepareEnvironmentVariables(),
       entry_maker = function(entry)
         local cols = vim.o.columns
-        local width = conf.width
-          or conf.layout_config.width
-          or conf.layout_config[conf.layout_strategy].width
-          or cols
+        local width = conf.width or conf.layout_config.width or conf.layout_config[conf.layout_strategy].width or cols
         local tel_win_width
         if width > 1 then
           tel_win_width = width
@@ -34,32 +31,29 @@ local function showEnvironmentVariables(opts)
         local command_width = 22
 
         -- NOTE: the width calculating logic is not exact, but approx enough
-        local displayer = entry_display.create {
+        local displayer = entry_display.create({
           separator = " ▏",
           items = {
             { width = command_width },
             { width = tel_win_width - desc_width - command_width },
             { remaining = true },
           },
-        }
+        })
 
         local function make_display(ent)
-          return displayer
-          {
+          return displayer({
             { entry[1] },
             { entry[2] },
-          }
+          })
         end
 
-        return
-        {
+        return {
           value = entry,
-          display =  make_display,
-          ordinal = string.format('%s %s', entry[1], entry[2])
+          display = make_display,
+          ordinal = string.format("%s %s", entry[1], entry[2]),
         }
       end,
-
-    },
+    }),
     sorter = conf.generic_sorter(opts),
     attach_mappings = function(prompt_bufnr, map)
       actions.select_default:replace(function()
@@ -74,9 +68,9 @@ local function run()
   showEnvironmentVariables()
 end
 
-return require('telescope').register_extension {
+return require("telescope").register_extension({
   exports = {
     -- Default when to argument is given, i.e. :Telescope env
     env = run,
-  }
-}
+  },
+})