[features]: A design of local project

[lvyuemeng]

Prefer the local project style.(rather virtual envs.)
Storing env metadata in project location (mimic to pixi).

{
  "manifest_path": "path to project env setting",
  "environment_name": "...",
  "xlings_version": "...",
  "environment_lock_file_hash": "..."
}

use lock_file_hash to avoid entire copy with lazy evaluated(update when hash isn't equal).

-- local project locked file.
env = {
     deps = {...} -- store packages.
} 

-- local project setting file.
project = {
   authors = "...",
   description = "...",
   name = "...",
   ...
}  
-- further discuss the role of xlings in design.(in which extent of role should xlings take over?)
-- should we make local installation? (not recommend) prefer a local path modification.(open a new transient shell or `xlings run (certain cmd)` (for example: xlings run cargo run).)
-- prefer a general parser for toml.(or others rather than raw lua file.)

[lvyuemeng]

Recommend a general parser for toml, yaml etc...