chore(development): add vim modelines to bin/* (#10183)

This adds vim modelines to our lua scripts in bin/ to identify their
filetypes and set the proper indentation settings.

I wish this could be done without cluttering up files with comment
strings, but .editorconfig does not have any notion of "treat this file
as $filetype." I have updated .editorconfig with the proper settings for
these files, however.

.editorconfig

@@ -20,3 +20,15 @@ indent_size              = 4
 
 [Makefile]
 indent_style             = tab
+
+[bin/kong]
+indent_style             = space
+indent_size              = 2
+
+[bin/busted]
+indent_style             = space
+indent_size              = 2
+
+[bin/kong-health]
+indent_style             = space
+indent_size              = 2

bin/busted

@@ -61,3 +61,5 @@ require("kong.globalpatches")({
 
 -- Busted command-line runner
 require 'busted.runner'({ standalone = false })
+
+-- vim: set ft=lua ts=2 sw=2 sts=2 et :

bin/kong

@@ -7,3 +7,5 @@ pcall(require, "luarocks.loader")
 package.path = (os.getenv("KONG_LUA_PATH_OVERRIDE") or "") .. "./?.lua;./?/init.lua;" .. package.path
 
 require("kong.cmd.init")(arg)
+
+-- vim: set ft=lua ts=2 sw=2 sts=2 et :

bin/kong-health

@@ -75,3 +75,5 @@ end
 
 
 run(arg)
+
+-- vim: set ft=lua ts=2 sw=2 sts=2 et :