Add build keywords

[al1-ce]

When making a task supply keywords for auto-insertion Aka:

Lua_Run FILEPATH:
    lua $1

With file at ~/script.lua be ran as

lua ~/script.lua

Without prompt for arg

Possible constants (taken from nvim async run)

$VIM_FILEPATH - File name of current buffer with full path 
$VIM_FILENAME - File name of current buffer without path 
$VIM_FILEDIR - Full path of current buffer without the file name 
$VIM_FILEEXT - File extension of current buffer 
$VIM_FILENOEXT - File name of current buffer without path and extension 
$VIM_CWD - Current directory 
$VIM_RELDIR - File path relativize to current directory 
$VIM_RELNAME - File name relativize to current directory 
$VIM_ROOT - Project root directory 
$VIM_CWORD - Current word under cursor 
$VIM_CFILE - Current filename under cursor 
$VIM_GUI - Is running under gui ? 
$VIM_VERSION - Value of v:version 
$VIM_COLUMNS - How many columns in vim's screen 
$VIM_LINES - How many lines in vim's screen 
$VIM_SVRNAME - Value of v:servername for +clientserver usage 

Other possible constants:

TIME
DATE
DATETIME
TIMEDATE
USERNAME
DISTRO
OS

[al1-ce]

Plus support for Any file type