Added gradle support to docs (jetify-com#182)

## Summary
Title says it

## How was it tested?
No need for testing only markdown files were changed

devbox 0.0.7

devbox 0.0.6

devbox 0.0.5

[planner] Optimize nodejs final image size (jetify-com#89)

## Summary
Optimize nodejs final image size by getting rid of dev packages in the
final image.
I'm open to a better schema if postCommandHook is not the best way to go
about it.

Tried it on a fairly complex NodeJS web app:
- size before: 837 MB
- size after (with yarn): 519 MB
- size after (with npm): 515 MB

Sample planner output with yarn:
```
{
  "install_stage": {
    "command": "yarn install",
    "input_files": [
      "package.json",
      "yarn.lock"
    ]
  },
  "build_stage": {
    "command": "yarn build && yarn install --production --ignore-scripts --prefer-offline",
    "input_files": [
      "."
    ],
  },
  "start_stage": {
    "command": "yarn start",
    "input_files": [
      "."
    ]
  },
  "dev_packages": [
    "nodejs",
    "yarn"
  ],
  "runtime_packages": [
    "nodejs",
    "yarn"
  ]
}
```

Sample planner output with npm:
```
"install_stage": {
    "command": "npm install",
    "input_files": [
      "package.json"
    ]
  },
  "build_stage": {
    "command": "npm prune --production",
    "input_files": [
      "."
    ]
  },
  "start_stage": {
    "command": "node index.js",
    "input_files": [
      "."
    ]
  },
  "dev_packages": [
    "nodejs"
  ],
  "runtime_packages": [
    "nodejs"
  ]
```

## How was it tested?
`devbox plan`
`devbox build`

devbox 0.0.4

+ When in a devbox shell, devbox packages take precedence
  over other binaries in your laptop. Previously there could be
  some interferance from binaries installed with other software
  like brew or asdf.
+ Better indication that you're in a devbox shell by prepending
  `(devbox)` to your prompt.
+ Support for `podman` as an alternate engine to build containers
+ Better support for older versions of docker.
+ Better error messaging when nix is not installed
+ Go version detection when building `go` containers

Note that we now also have docs site:
https://www.jetpack.io/devbox/docs/

devbox: add nix installation check to all commands (#2649)

## Summary
devbox: add nix installation check to all commands

## How was it tested?
go build
devbox shell

## Is this change backwards-compatible?
Yes

Version 0.0.3

Fast follow based on community feedback:
+ Improve the speed of the first call to devbox shell
+ Add console output explaining what's about to happen
+ Better error message when nix is not installed or in PATH
+ Error on "shell-inception". When calling devbox shell and
  you're already in a devbox shell.

[devbox] Add information to the README on how to join our Discord (#2…

…607)

TSIA

Release devbox version 0.0.2