Add chroot environment doc for minio (#5366)

Fixes #4659

docs/chroot/README.md

@@ -0,0 +1,40 @@
+# Deploy Minio on Chrooted Environment [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io) [![Go Report Card](https://goreportcard.com/badge/minio/minio)](https://goreportcard.com/report/minio/minio) [![Docker Pulls](https://img.shields.io/docker/pulls/minio/minio.svg?maxAge=604800)](https://hub.docker.com/r/minio/minio/) [![codecov](https://codecov.io/gh/minio/minio/branch/master/graph/badge.svg)](https://codecov.io/gh/minio/minio)
+
+Chroot allows user based namespace isolation on many standard Linux deployments.
+
+## 1. Prerequisites
+* Familiarity with [chroot](http://man7.org/linux/man-pages/man2/chroot.2.html)
+* Chroot installed on your machine.
+
+## 2. Install Minio in Chroot
+```sh
+mkdir -p /mnt/export/${USER}/bin
+wget https://dl.minio.io/server/minio/release/linux-amd64/minio -O /mnt/export/${USER}/bin/minio
+chmod +x /mnt/export/${USER}/bin/minio
+```
+
+Bind your `proc` mount to the target chroot directory
+```
+sudo mount --bind /proc /mnt/export/${USER}/proc
+```
+
+## 3. Run Standalone Minio in Chroot
+### GNU/Linux
+```sh
+sudo chroot --userspec username:group /mnt/export/${USER} /bin/minio --config-dir=/.minio server /data
+
+Endpoint:  http://192.168.1.92:9000  http://65.19.167.92:9000
+AccessKey: MVPSPBW4NP2CMV1W3TXD
+SecretKey: X3RKxEeFOI8InuNWoPsbG+XEVoaJVCqbvxe+PTOa
+...
+...
+```
+
+Instance is now accessible on the host at port 9000, proceed to access the Web browser at http://127.0.0.1:9000/
+
+## Explore Further
+- [Minio Erasure Code QuickStart Guide](https://docs.minio.io/docs/minio-erasure-code-quickstart-guide)
+- [Use `mc` with Minio Server](https://docs.minio.io/docs/minio-client-quickstart-guide)
+- [Use `aws-cli` with Minio Server](https://docs.minio.io/docs/aws-cli-with-minio)
+- [Use `s3cmd` with Minio Server](https://docs.minio.io/docs/s3cmd-with-minio)
+- [Use `minio-go` SDK with Minio Server](https://docs.minio.io/docs/golang-client-quickstart-guide)